A Hard Day's Night: Solving a Beatles mystery with mathematics

“Later on in the song, you can clearly hear a piano doubling George Harrison’s lead guitar solo. So I thought, maybe there is a piano in the song.

“A piano typically has three strings tuned identically corresponding to each note, and a hammer hits them. So perhaps those three frequencies could come from a single note on the piano.”

Dr Brown ran down to his local music store to test if his hunch was true.

“Before I got thrown out of the store by the manager, I managed to determine yes, it was possible, and it actually told me a little deduction about the piano used in the Abbey Road Studios to record that chord.