Paul McCartney wrote Cayenne in the late 1950's or in 1960. It has always been credited just to "McCartney" as opposed to "Lennon/McCartney," indicating that it is a pre-Beatles composition though recorded after their collaboration had begun.
It first came to light in a recorded jam session at Paul's Liverpool house in the Spring or Summer of 1960. The original recording is two minutes, 24 seconds long.
Cayenne is completely instrumental. Stuart Sutcliffe plays the bass in this recording. (The three other members play guitar.)
A sped up and shortened version appeared in the 1995 release of Anthology 1. The name "Cayenne" is considered provisional, as the song has also appeared in some bootlegs as Looking Glass, and official confirmation and explanation has not yet come forward.