According to my lights, classical music grates to the point of repugnance, so “The Undivided Five” is a distinct surprise. Poised on the edge between ambient music and a traditional classical bent, the album broods and sweeps and settles in an unhurried tempo that has made it one of my go-to deskwork supports. The band of seven words is actually a duo, Adam Wiltzie and Dustin O’Halloran, both of repute in the ambient and classical fields, and this is their second outing (at least in this incarnation) since their 2011 debut. Opener “Our lord Debussy,” combining to perfection muted sonorous piano chords and washing strings, is a ten-minute stately triumph that I can’t stop playing. After three slow eerie tracks, “Aqualung, motherfucker” belies its title with ebbing and flowing strings. Later, “The rhythm of a dividing pair” etches an almost invisible melody over fuzzy analogue synths. The lack of any balancing harshness or rhythmicity robs “The Undivided Five” of a standout rating, but if soft ambient music is balm to your ears, I recommend this unreservedly.