Interstellar Space was one of the final studio albums recorded by the saxophonist John Coltrane before his death in 1967, originally-released posthumously by Impulse! Records on LP in 1974.
Interstellar Space consists of an extended duet suite in four parts with the drummer Rashied Ali, and was recorded at the Van Gelder Studios on February 22, 1967, the week after the session that produced Stellar Regions. As a result, the melodies often overlap; "Venus" has the same melody as the title track of the previous LP, "Mars" quotes the melody of what became known as "Iris", and many note choices and runs are similar.
The structure of each track is fairly uniform: Coltrane plays some largely ceremonial wind-chime like bells, while Ali sets a shifting pattern on the drums; then the theme is stated by Coltrane on tenor saxophone. The album is an important example of highly improvised free jazz, which was Coltrane's principal interest in the latter part of his career. Coltrane's improvisations are thus extremely free here, stating tacit modes and harmonies briefly and modulating constantly, fitting extremely dense, twisting expressions into breath-length phrases. The folkish "Venus" is probably the most accessible number; "Saturn", the longest piece, does feature hints of swing by song's end. Its melody is rather similar to the canonical, almost cantor-like quality of the material on Stellar Regions.