Conversation so far:
Does Medley refer to a song on the album?
Side two contains a 16-minute medley of eight short songs, recorded over July and August and blended into a suite by McCartney and Martin.
Were the 8 songs previously recorded or new?
Some songs were written (and originally recorded in demo form) during sessions for the White Album and Get Back / Let It Be, which later appeared on Anthology 3.

Question: Did anyone besides McCartney and Martin have a hand in creating the song?
Self-contained rewrite: Did anyone besides McCartney and Martin have a hand in creating the song Medley?