A Rainbow in Curved Air

"A Rainbow in Curved Air" is the first side of the album, 18:39, written by Riley and not issued as a single. It was recorded in 1968 at Columbia Studio B in New York by Riley alone: electric organ, two electric harpsichords, dumbec and tambourine, overdubbed, with no downbeats and a non-tempered tuning. Wikipedia describes its basis in jazz improvisation and an interest in Hindustani classical music, with Bill Evans's overdubbed Conversations with Myself (1963) as an earlier influence.

Our upload is a full-album video, so the title track is part of it. A 2007 performance, A Rainbow in Curved Air (Revisited), with William Winant and Mikhail Graham, is claimed on Wikipedia but tagged as failing verification. The album's music has been used in the radio station The Journey in Grand Theft Auto IV (2008), and reportedly in other media, which Wikipedia marks as needing citations. We found no setlist.fm count and could not check covers or samples.