You all know it when you hear it: the most famous chord in rock that reverberates on George Harrison’s 12-string Rickenbacker: the opening of “A Hard Day’s Night”.
All this time, no one has known exactly what chord Harrison was playing. I can attest, as a musician in a band that tried to play the song, that the chord is elusive and not properly documented. And so it turns out that a Dalhousie mathematician has figured out the exact formula (see “Mathematician Cracks Mystery Beatles Chord“). What accounts for the problematic frequencies that, when put together, equal a chord not possible on George’s 12-string, John’s 6-string, and Paul’s bass? There was a piano in the mix, played by George Martin. Genius that he is, Martin added a piano chord that included an F note impossible to play with the other notes on the guitar.
Is this cheating? No, this is innovation at its finest: the resulting chord was completely different than anything ever heard before. And it proves that the fifth Beatle — George Martin — was a genius.