About that famous guitar chord.

A mathematician discovers the secret of the opening chord in "Hard Day's Night":

Four years ago, inspired by reading news coverage about the song’s 40th anniversary, [Jason] Brown decided to try and see if he could apply a mathematical calculation known as Fourier transform to solve the Beatles’ riddle. The process allowed him to decompose the sound into its original frequencies using computer software and parse out which notes were on the record.

It worked, up until a point: the frequencies he found didn’t match the known instrumentation on the song. “George played a 12-string Rickenbacker, Lennon had his six string, Paul had his bass…none of them quite fit what I found,” he explains. “Then the solution hit me: it wasn’t just those instruments. There was a piano in there as well, and that accounted for the problematic frequencies.”

Dr. Brown deduces that another George—George Martin, the Beatles producer—also played on the chord, adding a piano chord that included an F note impossible to play with the other notes on the guitar.

(Via Metafilter.)