"Fallen Angel" is the last King Crimson recording to date to feature Robert Fripp playing acoustic guitar. On subsequent recordings, he has played only electric guitar. The song began as part of an extended instrumental improvisatory piece performed by the original 1972–74 line-up with Jamie Muir and David Cross. A version of this early piece, also titled "Improv: Fallen Angel" can be heard on the King Crimson Collectors' Club release "Live at the Zoom Club October 1972". There is also a performance of "Improv: Fallen Angel Hullabaloo" on CD5 of the 2012 Larks' Tongues in Aspicbox set - "Hull Technical College - November 10, 1972".