A couple days ago, I learned the chords for "You Know What to Do." According to the liner notes of Anthology 1, it's a demo of a George Harrison song that the Beatles never properly recorded. In any case, I noticed some connections between the chord progression and the lyrics in the bridge.
To start with, here are the chords (with the disclaimer that - as always - I might have something wrong). There's an initial D major before the first verse.
Verses:
|: A major | E major :|
Choruses:
|: A major | E major :| A major | D major
Bridge:
B minor | D augmented | A major | D major
The chord progression is comprised of major chords until the bridge, which starts with a B minor. Appropriately, the mood in the lyrics also changes here: "Just call on me when you're lonely." Following that B minor is a D augmented, with an A# accidental that also contributes to the desolate feeling of loneliness.
There's a parallelism (of sorts) between the first and last lines of the bridge, both lyrically and musically. The lyrical parallelism is obvious: "Just call on me when you're lonely" is only a few words different from "I'll call on you if I'm lonely too." The "too" emphasizes the similarity. The musical parallelism is a bit obscure (and less exact). There's a B minor played for the entire first line, and there's a D major at the very end (corresponding to the "too" in "I'll call on you if I'm lonely too"). These are closely related chords: B minor is the relative minor of D major, and D major is the relative major of B minor. So in the bridge, there's a close relationship between the first and last lines and between the first and last chords. Accordingly, the speaker/singer wishes for a close relationship between himself and the girl to whom he addresses the song.
