"When I'm Sixty-Four" is a love song by The Beatles, written by Paul McCartney (but co-credited to John Lennon) and released in 1967 on their album Sgt. Pepper's Lonely Hearts Club Band. It is sung by a young man to his love, and is about his plans of growing old together with her.
The song prominently features a clarinet trio (two B-flat soprano clarinets and a bass clarinet), unusual in most music genres, but particularly in the context of rock and roll. Supporting instruments include the piano, (plucked) cello, chimes, and electric guitar.