This one is sort of a cheat. The Heliocentric Worlds Of Sun Ra, Volumes 1 and 2 were issued on separate LPs in 1966, while Volume 3 was compiled from previously unreleased session tapes in the 2000s, and they were all combined into this three-CD set in 2010. But each volume is different from the others, and they’re all equally essential, so this is the way to approach this material.

The music on Volume 1, recorded in spring 1965, is broken into seven shortish tracks, ranging from 1:56 (“Dancing In The Sun”) to 7:40 (“Outer Nothingness”). Some of them are free but swinging, while others are abstract and blaring. Volume 2 is even more extreme, containing an 18-minute piece, a 15-minute piece, and a five-minute interlude between them. Volume 3 splits the difference, with four pieces each running between four and six minutes, and one 17-minute epic. Among these 15 tracks you get a little bit of just about everything Sun Ra ever did, from loopy large-ensemble charts (the Arkestra — that’s what he called his band — had 11 members at this time) to spacey synthesizer tones to clattering percussion eruptions. The only thing not heard here is the human voice; many Sun Ra songs had lyrics, and others featured chanted slogans, but none of that was recorded for the Heliocentric albums, which were entirely instrumental.