As the title suggests, repetition is an important part of these tracks. The general structure sees one pattern repeated with small variations: adding reverb, finding new resonance or adding another blast of noise. "Fragment" has one base pattern of rhythmic noise gradually growing more intense and topping out after three minutes. "Order" repeats the trick over twice the length. The use of side-chain compression dominates many tracks, especially "Instant." It's a technique as over-used as any in modern dance music but, even at slow tempos, Emptyset use it in pursuit of barely-restrained aggression rather than softened grooves.
The title track might be the most interesting thing here. The tempo is higher, the tones approaching white noise in their fullness. When the sub hits it's the album's most cathartic, overwhelming moment. "Limit," which closes the album, is just as fast and even more hard-hitting, but you're somewhat better prepared for it. It makes the album as a whole mirror the structure of individual tracks—building to an impasse and stopping at its peak.
Recur isn't incredibly different from the past few Emptyset releases, but their style remains so singular that it's hard to fault them for it. Even without the backstory of adventurous field recordings, the key element here is still space. Purgas and Ginzburg have an ability to turn the listener loose in an acoustic territory, however it is created, and to warp the scope and scale of the sound-field with dramatic drop-outs and unexpected turns. Their music still sounds futuristic, not as some referential pastiche but something genuinely alien, and that alone is reason enough to listen.