When I'm Sixty-Four
The song was nearly released on a single as the B-side with either "Strawberry Fields Forever" or "Penny Lane" as the A-side. Instead, Martin decided on a double-A-sided-disc. The single did not make #1 in the UK, breaking a string of #1 singles going back to 1963. If "When I'm Sixty-Four" had been issued as a B-side, it probably would not have appeared on Sgt. Pepper.