[3] Guitarist Robert Fripp and drummer Bill Bruford initially disliked the song and declined to record it for that album;[4][5] instead, the group chose an instrumental improvisation as the title track.
However, the song was revived during subsequent touring between March and May 1974, with its lyrics altered and a long instrumental section based on a bass riff written by Bruford added to it.
The song's final section begins with an abrupt transition to a fast, jazzy saxophone solo with distorted guitars and bass, expressive tribal drumming, and the tempo doubling up to a time signature of 13/16.
The saxophone returns to play a reprise of the vocal melody, then the final section is repeated with more overdubs from Fripp.
Finally, the song ends with a reprise of the opening melody, removing the guitar in favour of a deeper bass.