Billy Preston will always be remembered as the Fifth Beatle because he played keyboards on Let it Be, The White Album and Abbey Road. There were others who aspired to that lofty title, and John Lennon once asked him to join the band, but the idea was dismissed by the others, since the Beatles were on the verge of a breakup anyway, after recording Let It Be.
One of Billy Preston's most famous songs is You Are So Beautiful, performed by Joe Cocker.
I remember him most well from The Concert for Bangladesh. It was released as a movie in 1971 and I took my girlfriend to see it. Back then, I went out and bought the album and 8-Track. It was great music - and still is.
Billy is with the Fab Two now, John Lennon and George Harrison. Long live Paul and Ringo. Long live the Beatles.