Paul played a toy piano on “The Fool on the Hill.”

Yes, that’s the song. McCartney picked out the melody on a small child’s toy piano during the recording sessions for Magical Mystery Tour. It gives the track that delicate, slightly out-of-tune bell-like sound you hear in the verses.

A lot of people assume it’s a celesta or a harpsichord. Nope — just a cheap plastic toy piano, probably intended for a five-year-old. Paul played it himself because it had to sound childlike, and a real instrument would’ve been too clean.

It’s one of those little Beatles details that makes you smile every time you hear it.