"Ladies and gentlemen, good evening and welcome," a man's voice booms in Spanish from the tower of speakers behind me. Dramatic sound effects are surging in the background—a cacophony of lasers, air horns, explosions, jet engines. Rainbow beams of light dance in the dense clouds of smoke, streaking over the heads of 1,000 people packed shoulder-to-shoulder under a tall tent.

To my left, a circle has formed. A man in a white dress shirt is twirling his dance partner under a yellow spotlight. They are dancing to the ecstatic cumbia beat of "En La Lejanía" ("In The Distance"), a 1969 classic from Los Wawancó, a legendary tropical music group.

In front of me, a group of young men has pushed their way to the metal barrier at the front of the stage. They're vying for the attention of the sonidero ("sound man"), Sonido La Conga, who's headlining the night. They're passing pieces of paper with hand-written messages to the sonidero's assistants, who take them to the stage and hold them in front of his face.

He cuts the volume on the DJ mixer, picks up the microphone, and reads one: "A shout-out to Luis and Daniela from their father, Edgar, who has joined us all the way from Toluca!" He introduces the next song, fires off more sound effects, and the dancing continues.

The party is taking place on a blocked-off residential street. There are kids watching from roofs and balconies. There is no cover charge, no security and the tent is lined with vendors selling giant micheladas—beer with lime juice, salt and a pungent seasoning sauce to give it a savory kick. In the distance, you can occasionally see an airplane landing or taking off from the Mexico City International Airport, which is only six blocks away. Peñón De Los Baños, a working-class neighborhood, is one of the crucial sites for Mexico's sonidero culture, a DJ tradition that goes back to the 1950s.

Sonidero parties aren't all bewildering spectacles. There are sonideros DJs big and small; some who play local birthday parties and some who tour the country with a 16-wheeler full of speakers. Some younger DJs take a modern, electronic approach to the sonidero sound, and some older purists only play music from the '50s and '60s. There are obsessive record collectors who repair their own turntables and casual fans who don't even own a DJ controller. Like any musical milieu, the sonidero universe contains multitudes.

What makes a sonidero a sonidero? Musical tastes vary, but they mostly share one thing in common: cumbia. The genre, which was born from the mingling of African and indigenous music in Colombia during the first half of the 20th century, has since spawned countless variations across the Americas.

There's the psychedelic twang of 1970s Peruvian cumbia, sometimes called chicha, which paired surf-rock guitars with more traditional rhythms. There's the older folkloric sound of Colombian groups like Los Gaiteros De San Jacinto, a rootsy style played with wooden flutes and hand drums. There's cumbia villera, from the slums of Argentina, a synth-heavy variation that, like gangster rap or reggaeton, has been decried as vulgar and corrupting.

The term cumbia sonidera could refer to a few generations of Mexican music, but its modern iteration involves more software than live instruments. This particular offshoot, characterized by synth melodies so colorful they're almost cartoonish, was captured on last year's excellent compilation ¡Un Saludo!—Mexican Soundsystem Cumbia In Los Angeles.

Some sonideros play more Cuban salsa than Colombian cumbia. Some only play tracks by Mexican cumbia bands. Others play big-room EDM remixes that sample cumbia classics. But as a general rule, the backbone of this tradition is the unmistakable cumbia beat of the guacharaca, a hollow tube that's scraped with a fork to form the genre's rhythmic foundation: chik-chika-chik-chika-chik. The melodies—sweet and potent like a rich dessert—are simple enough to have you whistling the hook after only one listen. Generally, cumbia isn't so much about virtuosity, or even originality, as much as sheer irresistibility. Unlike salsa, it doesn't require a jazz musician's musicality—just catchy hooks, charisma and the ability to keep a beat.

There's no rule that says you can't dance by yourself, but a good partner-dancer gets as much respect as a good DJ. Both play a role in the scene, and they're mutually reinforcing. Like checkers, the basic step is easy to grasp, but the turns, the gestures and the many stylistic accents can take a lifetime to perfect.

Sonideros who don't have their own soundsystem aspire to, and those who do are continually adding and upgrading to give it more juice. They're sometimes fine-tuned for clarity, but that's not really the point for many sonideros—they're just supposed to be loud. At first glance, it's not so different from Jamaican soundsystem culture, with sound men competing to see who can stack the tallest rigs and draw the largest crowds. It's got the same big egos and beefs that can lead to lifelong rivalries.

Then there's the talking. A sonidero isn't just a DJ. They must also be a great orator, an entertainer with the charisma to keep the people engaged from start to finish. A key aspect of this whole phenomenon is the saludos, which are the shout-outs that people request by passing along pieces of paper with messages written on them.

Some saludos are addressed to people who are at the party, often to super-fans who follow their chosen sonideros to gigs in different cities. But people also request saludos for friends and family members in the United States or Canada. They'll record the sonidero's shout-out on their phones, then send an audio message to let them know they're in their thoughts, even though they're separated by a border. Promoters will burn CDs with live recordings of the night and sell them to people as they're leaving, so partygoers can send shout-outs by mail.

The sonidero tradition is familial and multi-generational. Sons, daughters, nieces and nephews are often drafted into the family soundsystem before they're old enough to work at Walmart. Of course there are protective parents who want to keep their kids away from the bailes, and away from the dangerous neighborhoods with free-flowing beer and marijuana smoke. But there's often an older cousin or uncle who needs someone to carry their boxes full of records and cables.

That's how Danny Alvarado became Sonido Confirmación. "Next to my grandma's house lives my uncle Chucho," he says, "and ever since he was 13 years old he was working with the soundsystems from the neighborhood—Sonido Bacardi specifically."

The 30-something sonidero and I are sitting in the main plaza of a leafy residential neighborhood called Santa María La Ribera, just outside of the city center. Behind us is the Santa María Kiosk, an icon of the neighborhood. Imagine an outsized gazebo with a glass cupola, its high archways and columns painted in clay red and pastel blue. There's a bronze eagle perched on top of the dome.

"My uncle used to set up his soundsystem and play outside of my grandma's house," he tells me. "I would watch his parties from the roof, and I remember the first cumbia song that caught my attention was Los Mirlos' 'Cumbia De Los Pajaritos' ('Cumbia Of The Little Birds'). I loved that guitar part! After that, I heard it everywhere I went, and it always reminded me of my grandma's house."

His mother made it clear from early on that he was never to attend those parties. "She always used to say, 'Don't you go out there, Danny. Bad people show up to those parties,'" he says. But by the time he was 18, not even his mother could stop him, and he began to follow his uncle to bailes and block parties.

At art school a few years later, Danny picked the name Confirmación ("Confirmation") and decided to try his hand as a sonidero. For his first party, an end-of-semester celebration at the university, his uncle Chucho trucked over every piece of sound equipment he had. "Of course the audience was different from the block parties in the barrio," he says. "I mean, it was the National School Of Plastic Arts. But I've always felt comfortable working in either of those environments."

Danny is one of the few people I met in the sonidero scene who moves easily between worlds. He can DJ an art gallery in a chic neighborhood, or a dance music festival for a bunch of 20-somethings, but he's equally at home in the working-class neighborhoods that birthed this tradition.

"In the beginning I wanted to play in the barrio. That's how this project got started," he tells me. "But then it became something else, which is interesting because I get to bring a little piece of the sonidero world to a different type of audience, who may not be as familiar but they love it just as much."

Danny Alvarado alias Sonido Confirmación

For decades, tropical music like cumbia carried a class stigma. It's historically been seen as the music of the masses, and it's been treated with disdain by the upper classes, who often view music from abroad as inherently more sophisticated. Only in the last decade has it experienced a resurgent interest from the type of college-educated kid who might have previously listened to imported rock music. This slow process of destigmatization accounts for many of the new hybridized styles that pair cumbia tropes with modern rock or electronic music.

Danny's been able to ride this wave while also staying true to tradition. When a young promoter books him for a club gig, he often mixes the usual salsa and cumbia with less traditional fare: Afrobeat, Peruvian chicha, cumbia electrónica and psychedelic deep cuts from South America. But the way he explains it, the sonidero tradition—the way you'll experience it at a block party in Peñón De Los Baños—isn't just about playing your favorite tunes to a room full of people. A traditional sonidero plays a more complex, and more codified, role. As both the master of ceremonies and DJ (as well as the host of the party, in some sense), he or she is in charge of bringing the community together.

"It's essential for any sonidero that when someone who's well known in the neighborhood shows up, you give them a saludo," he explains. "You watch to see who's arriving at any given moment and you send them saludos, which keeps them there in the party because you acknowledged them. You made it known that such-and-such person is here, sort of like a toast to make them feel welcome."

House and techno DJs are expected to work with the crowd to keep them happy. A sonidero, however, must be even more deferent to the whims of the audience. If they're not dancing to your selections, if they don't like the way you talk over the music, if you're not giving enough saludos to the people making requests, you could face a career-ending disaster.

"Here's the difference between a DJ and a sonidero," Danny explains. "For some DJs it doesn't matter if the crowd likes it or not. But the sonidero has to build a connection with the public, because if they don't like it they're going to stop dancing, and then, well, you're done. I mean, sonideros are the voice of the barrio, you know? So the songs you're picking better be songs that the barrio is going to like."

A few people I spoke to complained about what they perceive as a rigidness in the Mexico City sonidero scene. They say the top sonideros all play the same time-tested tunes; they say they lack personal style and distinctive taste; that they don't take risks. Sure, you could call it conservative—it's a culture that values tradition over innovation, and in many ways it hasn't changed since the '80s. It's presided over by a handful of (mostly) men in their 50s and 60s who have been doing this for three to five decades, colossal figures who command respect in Mexico's working class neighborhoods.

The big ones, like Sonido La Conga, Sonido Condór or Sonido Fascinación, are businesses unto themselves, with branded trailer-trucks they use to transport equipment and huge teams of assistants who show up wearing matching jackets with logos. Arguably the most iconic of them all, the man who is synonymous with sonidero in Mexico City, is Ramón Rojo, alias Sonido La Changa.

It takes a while to track down Ramón, sending messages to various Facebook pages and calling disconnected phone numbers I find online. Finally, through Sonido Confirmación, I get a number for his daughter, Erika Rojo, who handles his publicity and bookings. She texts me back and says we could meet the next day in front of the Tepito metro station at 2 PM.

To get to the metro I walk down the Ribera De San Cosme, a main artery lined on both sides with tarp tunnels where street vendors hawk fried food and mass-produced goods. There's athletic gear, pirated DVDs, acrylic nails, sexy lingerie and USB sticks preloaded with low-bitrate MP3s. Almost every pharmacy or bank has a PA on the sidewalk. They're cranked to the highest volume, like they're competing for attention—one blaring '90s Mexican alt-rock, another playing New York salsa, the next playing Dutch trance. LED strips inside of the speaker cabinets flash pink and green and blue in time with the music.

That may sound overstimulating, but it's nothing compared to Tepito, where I emerge from the metro 40 minutes later to meet Erika Rojo. It's hot and bright and it hasn't rained in two months. The air is swirling with dust.

Outside of the metro stop it's chaos: more bootleg stuff, more tarps, more distorted speakers, more cars honking. It takes me half an hour to find her, even though we're criss-crossing the same one-block radius looking for each other. She gives me a hug and tells me her father's running late ("you know how the traffic is"), then guides me through the crowd to a fold-up table on the sidewalk that sells beer. It's early, but I order us each a liter, the only size it comes in.

Erika is funny and boisterous, and she's popular around these parts, waving every once in a while to people she knows. She spots an older woman and her granddaughter through the crowd and calls them over; they ask after each others' families and gossip for a bit, then they disappear into the throng. The phone rings and it's her dad, who's only a few minutes away, so I chug the rest of my giant beer and we set off through Tepito.

He's double-parked in a brand new sedan. I get in the front, Erika in the back, and we blast off onto the wide avenue, heading somewhere quieter, he says, to his favorite restaurant. Ramón, who's 68 and was born and raised in Tepito, has the energy of a man half his age. He's just as talkative and charming as his daughter, with a husky laugh and two tidy rows of white teeth.

Ramón Rojo, alias Sonido La Changa.

It takes half an hour to get to the restaurant, and in that time Erika's phone doesn't stop ringing. She takes calls about press opportunities and upcoming gigs. One promoter just confirmed a date 13 months in advance. Meanwhile, Ramón is complaining because, even though he's got three headlining gigs this week, plus appearances on morning TV and radio talk shows, he's still denied access to half of his fanbase: Mexicans in the United States.

"All they want is La Changa," he says. "The guys who already have their visas, El Condór or La Conga"—his competition—"they don't want them anymore. They want La Changa. You just say 'La Changa' and they'll pay whatever you ask. You can charge 50 dollars per ticket and they'll still sell out."

Ramón has toured quite a bit in the United States, always playing in cities with large Mexican communities. He and Erika lived together in Queens for three years; she went on to live in California, where two of her children still live with their father. "I lived like a king," he says. "We'd arrive in one city, play a show, then fly the next day. Los Angeles, Chicago, Atlanta, New York, you name it. We've seen all of America."

None of this work was legal. Each time he crossed the border he entered on a temporary visa, overstayed, and toured without reporting his income to the federal government. He was deported four times. The fourth time, in 2010, they got him as he was about to board a plane back to Mexico. His family was planning to pick him up at the airport but he never walked off the plane: he was in an immigration jail in Salt Lake City, Utah.

"They only held me for a month," he says, like it's no big deal. "And one day they said to me, 'Listen, we pulled your record. You're a famous artist. What are you doing here? If you're the best DJ in Mexico, why don't you just get your papers in check?'"

They let him go. But he now owes over $10,000 in fines and back taxes for the work he did illegally. If he ever wants to reunite with his fans in the States, he's going to have to rustle up the money. The irony of the situation, he says, is that if they just let him play a handful of US gigs, he'd be able to pay it all immediately—and a good lawyer on top of it.

"I was charging $5,000 per gig in the US," Ramón says. We pull up to the restaurant and he parks his car in the valet spot; the teenage attendant recognizes him and runs over to take the keys. "Now they're offering me $10,000. The promoters are practically begging for me to come, because they know there's money to be made. But if I don't pay those taxes, I can't get back to work. And I need to get back to work. This is my life, and it's how I'm going to die—as a sonidero."

We eat a big lunch. There are beers, dessert and coffee. Ramón gets nostalgic about his early days as a teenage music fan, in the 1960s. This was before Colombian cumbia took hold on Mexico, before the musical term "salsa" even existed. "We used to dance to danzón," he says, referring to the elegant partner dance that involves slow, precise footwork, "to mambo and guaracha, to rock & roll, too—Bill Haley & His Comets, Elvis Presley, Glenn Miller."

The late '70s and '80s are widely recognized as the golden age of the sonidero movement, at least for a particular generation. It was an explosive time for Latin music, with salsa establishing itself as the dominant sound of the Spanish-speaking world, and powerhouse labels like Colombia's Discos Fuentes taking tropical music to new levels of commercial success.

"In that era," Ramón tells me, "people really went out to dance. Not anymore. Now a lot of kids are out there robbing people who go out to dance. They're huffing mona"—a highly addictive paint thinner that causes nerve and organ damage—"and smoking weed, doing coke. The other day I was at a block party and I saw this group of girls, they couldn't have been more than 18, doing lines off the screen of a cell phone. They have this cocktail now where first you do a line, then with the other hand you take the mona, and after that you've got your 40-ounce beer. It's like a bomb!"

It's getting dark, and Ramón says he wants to show me something. We pay the bill, get the car and pull back onto the highway. He continues telling me about the good old days.

"We didn't used to have these huge soundsystems," he says. "Now people spend millions of pesos on lights and audio, which means you're investing more and making less." This is a critique that I hear from many seasoned sonideros—that these events have become too much about the sheer size and spectacle of the experience, and not enough about the music. That's why many of the hardcore heads, who don't want their music constantly interrupted by saludos, organize smaller events on weekend afternoons, where 30 or 40 people will gather in a park specifically to dance.

"We're here," he tells me. We're back on the margins of Tepito, pulling up to a trash-strewn park where half of the streetlights are out. We get out of the car, and I follow Erika and Ramón down the broken side walk, past a 15-foot statue of Rodolfo Guzmán Huerta, alias El Santo, a famous lucha libre wrestler from Tepito. Ramón has to raise his voice so I can hear him over the trailer trucks barreling down the dark boulevard.

We stop in front of a mural of names spray-painted in classic sonidero fonts, a look that's equal parts old-school sci-fi, graffiti and early heavy metal. "They put up this mural," he explains, "so that everyone who passes by can recognize the people that carried Tepito's name with them all over the world."

There's Adalberto Martínez, better known as Resortes, an actor and dancer who's widely credited with inventing the moonwalk, 40 years before Michael Jackson. There's Cuauhtémoc Blanco, a soccer legend who later became the mayor of a city called Cuernavaca, about an hour outside of Mexico City. There's Octavio "Fomoso" Gomez, a flyweight boxing champion who competed across North and South America. And then there's Sonido La Changa, which is what Ramón brought me here to see. He's beaming.

"One day," he says, "when I'm no longer part of this world, this mark will remain. It's a beautiful homage, to be recognized by the government as a pioneer of this movement that crossed so many borders. And look, it's here in my barrio, in Tepito—where I'm from, where I was born and where one day I'll die."

Family, tradition, community. These are the pillars upon which the culture rests. You could make the same generalization about Mexico as a whole, a country that in many ways runs on old-school values. Unfortunately, one of the old-school values that the sonidero scene can't seem to shake is its boys-club mentality.

"Everybody always asks me, 'Really? There are women sonideras, too?' Yes, they exist," says Marisol Mendoza, a promoter and cultural activist who runs a project called Musas Sonideras. We're sitting in the shadow of the Monument of the Mexican Revolution, a 200-foot triumphal arch with stone pillars and a copper dome.

"They've existed since the 1960s," she tells me. "Still, there aren't many. I have 43 women accounted for as part of the project, out of the one million sonideros there are between Mexico and the United States."

Sonido La Socia, who has since passed away, is widely acknowledged as Mexico's first woman sonidera. La Changa told me a story about how, in 1968, he borrowed La Socia's turntable and amplifier so he could play music outside of his uncle's record shop. One passerby happened to like his tunes, so she hired him to play records at her birthday party. It was his first gig.

Last September Marisol invited me to a party she organized on the rooftop patio of the Spanish Cultural Center. The dance floor was slammed when I stepped out of the elevator onto the third-floor terrace, with seasoned dancers doing flashy turns alongside amateur couples and punters who were just there to listen. You could tell the professionals from the way they moved, and from the color-coordinated satin and sequin outfits they wear for competitions.

A sonidera named La Chikis Salsera was at the controls, packed into the DJ booth with a large posse. True to her name, she was playing mostly upbeat, modern salsa tunes, taking occasional forays into slower styles like guaracha and guajira—classics from New York, Puerto Rico, Cuba, Colombia and Venezuela.

La Chikis Salsera

Throughout the night there was quite a bit of cumbia rebajada, which sounds exactly like it's translated: "cumbia slowed down." It's a Mexican invention that involves pitching Colombian records down eight or more beats per minute, sometimes even playing a 45 RPM record at 33 RPM. The singers' voices stretch like warm taffy and the accordions begin to drunkenly warble.

The sonidera would pick up her microphone every 30 seconds to send saludos, or to introduce the incoming song. She would duck the volume on the mixer to hype up the crowd: "Now let's dance, but with lots of flavor this time!" There would be a laser blast from her sound board, followed by the voice of a man announcing: "Ch-ch-ch-ch-ch-chikis Salsera!"

It's unusual to see one or two women sonideras on a lineup, let alone an entirely female bill. "Being a woman in this world is hard," Marisol says. "They're not as accepted, especially because there aren't many who have their own soundsystems. La Chikis Salsera, she uses her husband's audio—he's been working as a sonidero for years now. But it's also difficult because if you're married to a real macho then, well, if you get permission to go out and play, you go. But if you don't, you don't."

Though the crowd at the Spanish Cultural Center didn't seem to resist, Marisol tells me that it can be difficult as a woman to even get the dancers to take you seriously.
"You'll here these comments, like, 'Oh no, the women are playing tonight. We gotta go,'" she says. "People will say thing like, 'Why aren't you at home washing?' or 'You should be tending to your husband.' Often times when men play at an event, there's no remuneration. With women, even less. So you have to be courageous to go against the tide like that. You have to have this attitude, like, you don't intimidate me, because this is who I am and this is what I love doing."

Marisol's father is a long-time sonidero by the name of Sonido Duende. Though Musas Sonideras is fairly recent, she's also helped organize museum shows, academic conferences and online publications covering the sonidero movement. She dedicated almost ten years of her life to increasing the awareness of not just women sonideras, but of the entire sonidero culture, which has received strikingly little attention from the media, the academy and the rest of the Mexican music world.

One of the problems they're facing in Mexico City, she says, is that it's becoming harder to find outdoor spaces for bailes. "There are a handful of venues that we've been able to hold onto," she says, "but at any moment it could all be ruined by people behaving badly." In the neighborhoods where these block parties take place, promoters, the crowd and even the sonideros themselves run the risk of violence. "There are neighborhoods," she says, "where if somebody's asking for a saludo and you don't give it to them they might take out their pistol."

The city reacted by making it more difficult to do outdoor events. They've tried to corral crowds into proper nightclubs, where it's easier to keep security under control. But ask most fans and they'll tell you that bailes belong in the street, that they aren't the same if you put them in a private space with a cover charge. "The political aspect of this is really difficult," she says. "Really, really difficult. Because it's entertainment, and everybody has the right to entertainment, but it's just not something that the government considers in the scope of their political plans."

You don't meet a lot of foreigners in this scene, which is why I was keen to meet with Mirjam Wirz, a Swiss photographer and researcher who's been documenting it for eight years. Her first book, Sonidero City, was a photo collection chronicling Mexico and Colombia's sibling soundsystem cultures. Ojo Suaves, which came out last year, documents her tour around regional sonidero scenes in the Mexican provinces, accompanying one of the key figures in sonidero history, a record dealer and former music industry man named José Ortega. (The photos in this article are sourced from these books.)

On three separate trips, Mirjam and her coauthor, a musician and collector named Carlos Icaza, followed the route that José (who goes by the nickname Morelos) charted for them across the country. Through dozens of interviews in cities like Léon, San Luis Potosí, Puebla and Monterrey, they created an exhaustive oral history of the movement.

"In every place we visited during our trip, the music was a little different," she tells me. We're drinking tea at a busy cafe Downtown, on Avenida Balderas, a couple blocks from where the record dealers set up their stands in the afternoons and evenings. "In León, for instance, they play a lot of cumbia editada ("edited cumbia"), which is made on a computer, with electronic rhythms on top of older songs. In Léon they have some of the best dancers in the country, and they have their own dance called the paso-doble, which is a sequence of very fast steps that they only dance there."

After eight years spent deep inside the sonidero movement, Mirjam only recently found her footing as a dancer. "People would invite me to dance and I always said no because I didn't know the steps," she tells me. "It was embarrassing because I was always the only European and everybody would stare at me. They would say, 'It's fine, I'll teach you,' but then I'd start doing the turns and I'd lose track of the steps."

She eventually found the right teacher. "On Sundays in Peñón De Los Baños, there's a park where they put on dances in the afternoons," she says. "Morelos' cousin always goes there to dance. He's an older gentleman, very elegant, and he dances very well, and he's the one who taught me. I guess I just needed the right person to learn from."

Mirjam first got word of Morelos—who would become the main character in Ojos Suaves—in 2011 here on Avenida Balderas. She struck up a conversation with Jorge, one of the vendors who sells tropical records on the sidewalk. He said if she was interested in cumbia there was one person she absolutely needed to talk to. "Morelos and I met up the next day," she says, "and from there he took me to all of these different places. I started taking photos, meeting so many people, doing interviews during the day and at night accompanying him to his dances."

She already loved the music, but what struck her was the warm welcome she received. "Above all it's the people that really attracted me to this project," she says. "They're so open, so humble, and we just get along really well. They accepted me with open arms."

A couple days later I seek out Morelos for myself. I get his phone number from a friend of a friend, a Japanese expat who runs a tiny noodle shop near the Avenida Balderas. Morelos sometimes comes in to eat when he's buying or selling records nearby, and the two have become friends over the years. We meet there the next day for lunch. He walks into the cafe carrying a home-listening stereo in a cardboard box.

"I'm only going to comment on what I've lived," he says, in a mumbled barrio accent. On top of the accent and the old-school slang, he's also missing most of his teeth; I lean in and still only get half of what he's saying. "A lot of people will tell you lies—you know, 'My grandpa or my uncle did such-and-such.' Or they'll only tell you about their favorites. I'm going to tell you what I've lived."

At nearly 70 years old, Morelos exemplifies the archetype of the battle-scarred music obsessive who's seen it all before—the type of person who believes that music simply isn't as good as it used to be. He was born and raised in Peñón De Los Baños, the same poor-but-proud Mexico City neighborhood where I attended my first sonidero party. Its nickname is Colombia Chiquita ("Little Colombia") because it's where Colombian music, cumbia specifically, first took root in Mexico City. To this day, Peñón is ground zero for the capital's sonidero movement, with a vinyl shop dedicated entirely to tropical music, as well as huge block parties and smaller weekly get-togethers for serious dancers.

"In my mind," he says,"it started with Rubén Marquez, a gentleman from Colombia, who arrived to Mexico in '65 or '66. For better or worse, he landed in Peñón. I don't know why, maybe because it's right next to the airport. But he was the person who started everything. He was the linchpin for all of this music."

Morelos was born into a family of merchants, dealers who bought, sold and traded commercial goods. By the '70s, Colombian music had already established itself in neighborhoods like Peñón and Tepito, and crowds were demanding imported records from acts like Sonora Dinamita and Andrés Landero. Morelos' older brother saw an opportunity to cut out the middleman, and in 1977 he traveled to Colombia for the first time to bring back new releases without the help of a distributor. He began travelling there regularly, and by 1982 Morelos was joining him on these visits.

Morelos

Nearly four decades later, Morelos still buys and sells records for a living. For a while he was flying across Central and South America to dig for rare tropical records, many of which had gone out of fashion in their home countries. Now, in his old age, he trades strictly within Mexico, going through long-neglected collections in basements and attics, then selling records to private collectors, sonideros and the shops that set up over on Avenida Balderas. In the course of his travels he has forged many of the connections that tie together sonidero scenes in different parts of Mexico.

He only alludes to this, but for a time Morelos was also handing Colombian records to the bootleggers in Tepito. This was a time before budget airlines, when shipping costs were astronomical and imported records went for many times the price of those pressed domestically. Pirate labels, which pressed low-quality replicas of international records, flourished on Mexico City's black market, especially in Tepito.

"Listen, if you can't beat 'em, join 'em," he says. "I remember in '83 I had just arrived from Colombia, and I had a hit record with me. This guy Poncho says to me, 'Look, my mailman's here!' They didn't even give me a week to sell the record, because by the next day they had the bootlegged version out. And of course people chose the affordable option. That happened to me a few times."

Morelos also played the role of fixer for visiting musicians from Colombia. Mexico's always been one of Latin America's largest consumer markets, and since the second half of the 20th century, Central and South American musicians have set their sights on making it big with fans up north. Morelos brought a number of tropical music stars of the '70s and '80s to Mexico for their debut gigs.

"I brought vallenato to Monterrey," he says, referring to a rustic style of Caribbean cumbia that Monterrey musicians have come to adopt as their own. (Some even wear the sombrero vueltiao, a traditional farmer's hat from Colombia made with dried leaves.) "At the time everybody was listening to paseo, which was cowboy music. Then cumbia hit."

Monterrey, a mountainous city of five million near the Texas border, is another Mecca of Mexican sonidero culture. They have their own take on the sound, often with younger crowds and a computerized palette involving synths and drum machines. It's home to Celso Piña, one of Mexico's most iconic living musicians, and the undisputed king of their homegrown cumbia movement.

Piña's mid-'80s success, "Cumbia Sobre El Río" ("Cumbia On The River"), was given new life in 2001 when it was remixed by the Mexican hip-hop giants Control Machete. For a time in the early 2000s it was so ubiquitous that you couldn't go a week without hearing those accordions and 808s leaking out of cars, shops and nightclubs all over Mexico City. The track currently has 29 million views on YouTube.

"Who do you think told him to record 'Cumbia Sobre El Río?'" Morelos tells me. "Who do you think came up with that idea? You're talking to him, that's who."

The waitress comes over to take away our plates. Morelos, who's old enough to be her grandfather, makes a flirty remark and asks if she'll go out dancing with him. She rolls her eyes and makes a face like, he does this every time. I pay the bill and ask if he doesn't mind walking over to one of the record stands on the Avenida Balderas. He says he's got nothing else to do, so we set off on foot.

Of course he knows everybody at the record stands. He bums a cigarette from one of the vendors and tells him to give the gringo a good deal for whatever records I want. Most of the stands, which are just aluminum frames with tarp draped over them, have large sections of classic rock and metal. There's a ton of hi-NRG, the post-disco electronic genre that had a huge following here in the '90s and a crowd that overlapped with the sonidero scene. One stand on the corner specializes in tropical music. Morelos calls me over to a milk crate full of 7-inches and starts pulling records.

"This one's good, but it's pretty commercial. You could find it anywhere," he says, leafing through a box. "This other one here, the B-side is great. Here, wait, listen." The stand has a turntable plugged into a generator and he puts it on: "Toquen Cumbia" from 1975.

The thundering drums come first. They're matched by the guacharaca beat, a slinky chik-chika-chik like a hand saw being pulled back and forth. Then come the horns and the clarinets, raw, cacophonous and detuned, with such a vigorous presence that it's like someone's shaking you by the shoulders.

I put the record in my stack and Morelos keeps pulling, the burnt-down cigarette dangling from his mouth. We listen to a dozen more, not just cumbia but other vintage styles, some romantic ballads from the '50s, some Cuban son and danzón (the musical predecessors to salsa), a bit of bolero, some Latin jazz from New York. The record vendor sizes me up and tells me its 100 pesos per record, roughly five American dollars each. When I get home later that day I find the "Toquen Cumbia" 7-inch on Discogs for 80 dollars.

"Everything is so overpriced," Morelos says, when I ask him what he thinks about the vinyl market. "It's the Europeans' fault. They ruined everything. I'll sell a record for maybe 5,000 to 8,000 pesos"—250 to 400 dollars—"and that's nothing for some of these collectors. There's this one crazy guy in New York, I can tell you he'll easily spend 15,000 pesos. He must have a lot of money, no?"

In other countries that are hot with record collectors, like Panama and Argentina, Morelos says, the inflation is even worse. "These people are opportunists," he says. "I mean we all have to make a few cents to live, but this just isn't right."

Digging through the sidewalk bargain bins is an excellent way to spend a Saturday afternoon. But the real holy grails (with the price tags to match) are to be found way out in Peñón De Los Baños, at a vinyl shop called Discos Colombia Chiquita. There's only one room, with a low cement ceiling and a hand-painted sign in the colors of the Colombian flag. It's a dream for Latin music fans—the walls are lined with cumbia, salsa and rumba records ranging from the ubiquitous to the ultra-rare.

The shop's owner, Manuel Perea, alias Sonido Fascinación, is flipping through a box of rock LPs that a customer brought in, and by the look on his face it doesn't seem like he's buying anything. His middle-aged daughter Maria, who DJs under the name Sonido La Morena, is behind the counter.

"Right where you're standing," Manuel tells me, "in this little room, is where my mother gave birth to me 73 years ago. I christened this neighborhood Little Colombia back in the 1970s."

Manuel Perea, alias Sonido Fascinación

Manuel, who belongs to the pantheon of Mexico's pioneering sonideros, has been DJing since 1962. It was around the same time that he started selling records at the tianguis, the open-air flea markets where they sell everything from bike tires to used sneakers and power tools. Together with his brother Pablo, Sonido Arcoiris, he was one of the first record dealers to tour Central and South America in search of music, not just Colombia but Chile, Argentina, Peru and Venezuela. The Perea family is so established in Peñón (and in the sonidero scene at large) that they're generally referred to as la dinastía Perea, the Perea dynasty.

"We have music in our blood," he says. "Even my grandparents and great-grandparents were musicians. Of course going back that far we're talking about live, instrumental music—orchestras and ensembles. My father's father, who was born in 1903, was already a great violin maestro by 1920. That was before records even arrived in Mexico, when the dances were held with string ensembles."

The Perea dynasty doesn't end with Manuel. Of his eight sons and daughters, five of them are sonideros. Of his nephews, another five are sonideros. Manuel's son, Manuel Junior, recently took up the mantle of Sonido Fascinación, and now carries his father's legacy on tour across Mexico and the United States. These days, Manuel Senior mostly tends to his record shop.

I ask him how sales have been recently. "This is a working-class neighborhood," he shrugs. "That doesn't help much. But since we're right next to the airport, and we've got this big sign that says 'we sell vinyl records,' people will pass by in their cars, park a little ways up and then come in because they're curious. They're often surprised to see we still sell records. Most people threw theirs out ages ago."

Business has picked up thanks to the vinyl boom that's been gathering steam for the last few years. But a lot of the best records are lost, he says. There was a time in the '90s when longtime collectors were either giving away or throwing out records that they'll never find again in their life.

"When CDs arrived we were all enchanted by them. Even I caught the bug," he says. "Now people are pulling their hair out because they sold their records for almost nothing. They treated them like trash. Now we're realizing how much music we lost and we're trying to recover it."

Nearly every centimeter of wall space is occupied. The surfaces and shelves, too. It's not just records and CDs but amps, stereos, half-broken turntables, musical instruments and, notably, a souvenir shop's worth of Colombian paraphernalia. There's a Colombian flag, with a condor perched atop a gold crest, an entire wall of Colombian farmer's sombreros, a T-shirt that says, "Yo ❤️Colombia." As my eyes scan over the patchwork of blue, yellow and red, I ask him about the connection between the two countries.

"Colombia is like a wellspring of music," he tells me. "It'll always occupy first place for the sonideros, and we owe it very much for what it's given. But it goes both ways, in the sense that the Colombians are just as crazy for our music as we are for theirs. They love our huapangos, rancheras, boleros, trios. It's a musical exchange: you give a little, I give a little, you like mine, I like yours. And it keeps going like that."

An introduction to the sonidero sound

Danny Alvarado, AKA Sonido Confirmación, offers a taste of not only the tropical music you're likely to hear at a sonidero party, but the way these DJs use their voice to tie the tracks together, while hyping up partygoers with shout-outs and sound effects.