Tone Rec comes in two distinct flavors: downbeat rock-quartet riffs and expanses of background minutiae. The band’s trick, at which it succeeds tremendously on Thugny-Trugny (Sub Rosa), is to push the riff repetition until it achieves background stature — and to invest its environmental soundscapes with enough rhythmic elements (chirps, and clips, the beading of energy sources) to suggest a kind of momentum.