Spiritual Unity was the album that pushed Albert Ayler to the forefront of jazz's avant-garde, and the first jazz album ever released by Bernard Stollman's seminal ESP label. It was really the first available document of Ayler's music that matched him with a group of truly sympathetic musicians, and the results are a magnificently pure distillation of his aesthetic. Bassist Gary Peacock's full-toned, free-flowing ideas and drummer Sunny Murray's shifting, stream-of-consciousness rhythms (which rely heavily on shimmering cymbal work) are crucial in throwing the constraints off of Ayler's playing. Yet as liberated and ferociously primitive as Ayler sounds, the group isn't an unhinged mess -- all the members listen to the subtler nuances in one another's playing, pushing and responding where appropriate. Their collective improvisation is remarkably unified -- and as for the other half of the album's title, Ayler conjures otherworldly visions of the spiritual realm with a gospel-derived fervor. Titles like "The Wizard," "Spirits," and "Ghosts" (his signature tune, introduced here in two versions) make it clear that Ayler's arsenal of vocal-like effects -- screams, squeals, wails, honks, and the widest vibrato ever heard on a jazz record -- were sonic expressions of a wildly intense longing for transcendence. With singable melodies based on traditional folk songs and standard scales, Ayler took the simplest musical forms and imbued them with a shockingly visceral power -- in a way, not unlike the best rock & roll, which probably accounted for the controversy his approach generated. To paraphrase one of Ayler's most famous quotes, this music was about feelings, not notes, and on Spiritual Unity that philosophy finds its most concise, concentrated expression. A landmark recording that's essential to any basic understanding of free jazz.