The first time you entered a music store, chances are it was because there was one song you had to have.

Maybe it was "Set You Free" by N-Trance, "Pump Up The Jam" by Technotronic, "You Belong To Me" by JX or "Hungry Like the Wolf" by Duran Duran.

These days, finding that song, without buying many more that you don't want, is becoming increasingly difficult. Once the backbone of the business, singles sales totaled 31 million last year, down 41% from 2000, according to Soundscan. It's believed to be the lowest sales figure since the late 1940s, when singles were introduced on vinyl.

Singles aren't even made for many of the most popular songs because music companies think they're unprofitable.

Among Billboard magazine's 40 most popular songs the week of Feb. 23, only five were available as singles on compact disc. Eighteen were on sale just as vinyl records.

Seventeen songs, including Creed's "My Sacrifice," No Doubt's "Hey Baby," Enrique Iglesias' "Hero" and Alanis Morissette's "Hands Clean," were only available if you bought a full album.

Record retailers complain that this alienates fans, particularly young ones, by forcing them to spend more than they want or, worse yet, retrieve songs online.

"I think they're losing a whole generation of record buyers," said Carl Rosenbaum, chief executive of Top Hits, a Buffalo Grove, Ill., company that supplies music to 15,000 stores nationwide in America.

"You either have to steal it off the Internet or you just don't buy it at all," he said. "The other option is to buy a full CD for $20. If you're just introducing yourself to an act, you don't want to do that. It's hard to figure out what their thinking is."

Music executives, in turn, blame retailers for discounting singles so heavily that it's impossible to profit. "We can't work it out," said Val Azzoli, co-chairman of the Atlantic Group of labels. "We're not an industry that works together."

If the single dies altogether, the beginning of the end can be traced a decade back to the start of Soundscan, which provided the first precise measurements of music sales.

Executives who long suspected that singles cut into sales of the more profitable full-length CDs finally had evidence to back that up, said Jordan Katz, senior vice president of sales at Arista Records.

There's some debate about the extent to which that's true, though.

Bob Higgins, chief executive of the Albany, N.Y.-based Trans World Entertainment, which owns 950 music stores, said he believes singles hurt album sales in only about 15% of cases.

In the late 1990s there was a brief period when record companies put singles by singers such as Mariah Carey on sale for a money-losing 49 cents, artificially boosting sales to secure flashy chart debuts.

CD singles, which usually have two or three songs, generally retail for $3 to $4. Many retailers routinely discount them by 50% or more, Azzoli said. And there are still music companies that encourage this by secretly giving singles away to retailers to inflate sales, he said.

At Arista, Katz is sensitive to concerns on both sides and is among executives experimenting with ways to make more singles available, although maybe not in the way many consumers would want.

In some cases, singles are made available before an album's release but pulled from stores when the album comes out. Arista also makes singles for songs after they have cooled off as hits.

And labels are experimenting with "maxi-singles." They may contain five or six songs, often remixes of the same song, and are sold for $9 to $10. Their manufacturing cost is close to that of regular singles, so profits are higher.

"We have to get kids in the habit of buying music," Katz said. "I'm trying to figure out innovative ways to have singles and albums coexist."