<P> The song is in the key of D ♭ major . Recorded in C major, the master take was sped up to raise the key by one semitone at the insistence of McCartney . Martin remembers that McCartney suggested this change to make his voice sound younger . McCartney says, "I wanted to appear younger, but that was just to make it more rooty - tooty; just lift the key because it was starting to sound turgid ." </P> <P> The song was nearly released on a single as the B - side of either "Strawberry Fields Forever" or "Penny Lane". It was instead held over to be included as an album track for Sgt . Pepper's Lonely Hearts Club Band . </P> <Ul> <Li> Paul McCartney--lead and backing vocals, bass guitar, piano </Li> <Li> John Lennon--backing vocals, lead guitar </Li> <Li> George Harrison--backing vocals, guitar </Li> <Li> Ringo Starr--drums, tubular bells </Li> <Li> Robert Burns, Henry MacKenzie, Frank Reidy--two clarinets, bass clarinet </Li> </Ul> <Li> Paul McCartney--lead and backing vocals, bass guitar, piano </Li>

Who sang lead on when i'm 64