Mystery Chord Decoded

the beatles - HELTER SKELTER
http://www.youtube.com/watch?v=OM9KRpEkGfY

The Beatles - I Am The Walrus
http://www.youtube.com/watch?v=cqOKvonLrH8

The Beatles Hello Goodbye
http://www.youtube.com/watch?v=QShSmpI0r9k

The Beatles -- Help!
http://www.youtube.com/watch?v=9ibX3TejlZE

Beatles - I Wanna Hold Your Hand
http://www.youtube.com/watch?v=lfsvE4j4ExA

The Beatles - I Saw Her Standing There (1964)
http://www.youtube.com/watch?v=DNsmrd-aR1c

The Beatles - A Hard Day's Night (1964)
http://www.youtube.com/watch?v=84Gl3i6qAYo

“Hard Day’s Night” Mystery chord solved using math
http://www.noiseaddicts.com/2008/11/beatles-hard-days-night-mystery-chord-solved/