Reeds player, composer and Art Ensemble of Chicago co-founder Roscoe Mitchell recorded this mix of premeditation and improv with four trios in 2015, to mark the 50th anniversary of the Association for the Advancement of Creative Musicians. Reportedly, the occasion at Chicago’s Museum of Contemporary Art was a mixed-media experience. In audio form, extended stretches on disc one need close focus on quiet bell-chiming, long trumpet tones against multiphonic sax growls and slow-blooming high-reeds harmonies. The momentum cranks up on the title track, Dancing in the Canyon, and on the keys-centred EP 7849 (featuring pianist Craig Taborn). Disc two, however, is a rich testament to Mitchell’s wide horizons and enabling powers as an improvising player-composer. Here, the leader’s sinewy alto sax weaves amid turbulent bowed-bass figures. On the 25-minute finale, bagpipe-like circular breathing and free-jazz maelstroms segue into the grooving Art Ensemble anthem Odwalla.