The Unreleased Beatles: Music and Film by Richie Unterberger

"The Unreleased Beatles" details the incredible wealth of music the Beatles recorded but did not release, as well as film footage of the group that hasn't been made commercially available. A staggering amount of material is examined, from unreleased studio outtakes, BBC radio recordings from 1962-1965, live concert performances, home demo recordings, fan club Christmas recordings, and other informal demos done outside of EMI studios. The book includes chronological entries for all of the Beatles' unreleased recordings of note from 1957-1970, as well as all of the unreleased video footage of note from 1961-1970 and outtakes from 1990s interviews filmed for Anthology. There's also a general overview of Beatles bootlegs, Beatles songs recorded by other artists in the 1960s, and never-recorded material.