Composer/saxophonist Ken Thomson has been a key member of New York's classical scene in recent years. But when setting that pedigree to one side, this album feels like a breakout moment. Both pieces here, written for the JACK Quartet, show a composer who's capitalized on (and grown beyond) post-minimalist influences. "Perpetual" (Tracks 1-3) finds Thomson's own bass clarinet joining the quartet: the first movement ("underlying") is a slow-burner, while the second ("Bad idea") is the helter-skelter hailstorm, before the melodic close. "Thaw," for the quartet alone, is very nearly as good.