The back story to 4 Rooms isn't needed for an appreciation of the cold drone meditation of the album, but it does provide some unnerving context — the rooms in question, indicated by the track titles, are locations in the radiation zone still in place around the destroyed reactor at Chernobyl in Ukraine. The technical notes indicate that Jacob Kirkegaard's approach, openly citing Alvin Lucier's own work with tape overdubs, consisted of literally recording silence in each particular room — all chosen due to being popular meeting places before the accident — and broadcasting the results back into the room, many times over. Those familiar with the work of such sound artists like Thomas Köner will find immediate sonic affinities with 4 Rooms — the opening "Church" in particular sounds like a piece from Köner's mid-'90s works, with an air of metallic chill. It's not a tone maintained throughout 4 Rooms, but all have the same general air — if "Auditorium" feels a bit warmer in comparison, it's no less darkly meditative. Though not spelled out, presumably Kirkegaard further treated the recordings with understated arrangements, as the pieces shift to include undulating rhythms (without percussion) and shifts in volume, as well as fading out in some cases. "Swimming Pool," of the four pieces all told, might be the most gripping — while possessing similarities to "Church," there's an almost stuttering, nervous edge to the main drones, allowing one to not entirely relax. In contrast, the concluding "Gymnasium" is the most hollow-sounding and eerie, with a higher pitch lending to the distanced feeling throughout. In the end, the larger background of the album is somehow present in a wordless fashion throughout 4 Rooms, suggestive of sudden abandonment and a still-looming, potent threat.