There’s no doubting the credentials of these four éminences grises who, between them, have worked with major avant-gardists including Anthony Braxton, Paul Bley, Butch Morris and Sam Rivers. On this follow-up to the quartet’s 2019 debut, Bamako, there are a pair of intense group improvisations, both – in a new development for the group – given a raw edge by Haynes’ serrated electronic treatments. The rest of the tracks are original compositions, with each member contributing a couple each. Several of these push deep into the left-field: Haynes’ ‘The Other Side,’ summons a stately swirl in which he drenches his horn in acrid effects. And Altschul’s ‘Caring’ is a loose, somewhat austere abstraction that reminds of his role alongside Braxton, Dave Holland and Chick Corea in the out-jazz super-group, Circle. Even so, much of the real meat comes when they commit to more palpable forms and get in on a groove. Altschul’s title track (dedicated to Ornette) is a deceptively conventional hard-bop swinger with a big-grinned joie de vivre, while his ‘Da Bang’ (dedicated to Billy Bang) bursts out of an extended solo drum intro with an irresistible bass vamp heavy enough to establish its own gravitational field. Serious fun.