The Beatles: A Hard Day's Night -

: It is the only Beatles album where every song was written by Lennon and McCartney, with John Lennon serving as the primary author for nine tracks.

: The title track’s opening chord—variously described as an Fadd9 or a G eleventh suspended fourth —remains one of the most studied sounds in music history for its unique, "shimmering" quality. The Beatles: A Hard Day's Night

The soundtrack was a landmark in the Lennon–McCartney partnership, featuring 13 original tracks. : It is the only Beatles album where

: The lyrics often focused on the demands of fame and devotion, contrasting the exhaustion of their schedule with the sanctuary of personal relationships. II. The Revolutionary Film The Beatles: A Hard Day's Night