Porosity is the key. On gig night, Sly & The Family Drone might rock up as a group of three players or maybe nine, splaying themselves among the audience so that everyone in the room is essentially swept into honorary membership. Jamaica!! have no fixed lineup either, nor stylistic tenets to which they persistently adhere. Inclusivity is at the fore, which means modifying and creating their own instruments to render them accessible (as part of their ethos of “reshaping the round hole to allow the square peg to fit rather than the unfair expectations of the inverse”). On the night captured here – presented by The Gate, which is an arts project for adults with learning disabilities and where Jamaica!! was conceived – 16 players (including late addition Alan Courtis) produce a beautiful spillage of interwoven rhythms, blistering arches of saxophone, half-heard voices, catapulting tape delays, amplifier feedback and more, steered into multidirectional frenzy or unified gallop by the nuanced interactions of improvisatory committee. The last few minutes of side A form the sonic spectre of a runaway train embarking on breakneck chicanes, complete with distorted horn blasts that punctuate each teetering turn; side B picks up with a giddy congregation of sax and guitar with nudges of percussion keeping the whole thing just about upright, finally settling into a triumphant groove that seems to occur at three disparate tempos simultaneously. At points we have little blasts of warped hip-hop; at others, a squalling avalanche of spontaneous expression reminiscent of Arts Ensemble of Chicago. The whole thing is explosively joyful, making 16 players sound like 30 or 40, negating any worldly grimness by blotting it out for just a moment.