"When I'm Sixty-Four" is a song by the English rock band The Beatles, written by Paul McCartney (credited to Lennon–McCartney) and released on the 1967 album Sgt. Pepper's Lonely Hearts Club Band. It was one of the first songs McCartney wrote; he was about 14, probably in April or May 1956. The song was recorded in a different key from the final version; it was sped up at McCartney's request to make his voice sound younger. It prominently features a trio of clarinets (two B♭ clarinets and one bass clarinet).