Some of the best moments on Strength & Power sound like a group of musicians falling down the stairs. These tumbles, though, are interspersed with passages of real swing and groove; Rudd’s trombone, fun-loving and raucous, moves seamlessly between improv and older traditions (he grew up playing Dixieland and trad before working with Cecil Taylor, Archie Shepp, Steve Lacy et al); Pandi, likewise, turns on a dime from frenzy to almost-groove. Like Saft, and Dunn, the latter on double bass and a long way from his avant-rock origins with Mr Bungle, they have the strength and power the title suggests, but they can be tremendously subtle too. Often ramping up gradually but inexorably from delicate beginnings like a slow-motion avalanche, this is free improvisation as spontaneous collective composition: four musicians swooping unpredictably but forever in formation like a murmuration of starlings.