Dalhousie University (Nova Scotia) math professor Jason Brown has apparently solved a musical "who-dunnit" - what was the opening chord of the Beatles' famous Hard Days Night? There was an agreed upon suspect - namely George Harrison - but what was the chord? No one could reproduce it, even knowing what guitars they used in performances.
Enter Professor Brown. The professor used tools well known to forensic audio examiners - an FFT (Fast Fourier Transform) to analyze the spectrum and logic. And what did he deduce? It appears that George Harrision had a little help from someone else - perhaps the Beatles' manager, George Martin - who simultaneously played the chord on a piano! So, in the spirit of the board game Clue (Cluedo, for you Brits), it was George AND George, in the recording studio, with a guitar AND piano. Mystery solved!
Here is an article to read more about it. And another one. Enjoy!
(Hat tip to D.E. - thanks!)