When The Beatles were writing “Let It Be”, the punch-drunk members of the band experimented with word substitutions to sound out the melody before the lyrics were finalized. John Lennon in particular, found that using the first four letters of the alphabet was a good way to break it all down.
Let it A, Let it B, Let it C, Let it D
This scene took place during the same clip from the 1970 film Let It Be (and subsequently Peter Jackson‘s epic documentary The Beatles: Get Back) where Heather McCartney startled a focused Ringo Starr.
