Can we even call this a bridge? Is there even a chorus? It's almost more accurate to call it through-composed. There are verses, certainly, but then there's this long, two-part "bridge" for lack of a better word. No matter what you label it, the harmony is really interesting both in how it relates to the rest of the song and between the two bridge sections.
First, the move to C major from A major is pretty drastic, especially for a hit like this in 1964. It's interesting to note that C major is the relative major of the parallel minor, A minor. Got that? It comes into play moving into the second section of the bridge. The first section is a simple ii-V-I-vi-ii-V-I progression in C major, coming out of the signature E7 arpeggio bass line pretty much unprepared (though the bass line does feature E-D heavily). Simple as it is, you can also hear it as the doo-wop formula (I, vi, ii or IV, V) displaced by two measures.
As interesting as this new local tonic is, the way he gets back to A major is what really gets me. At the end of the line "Pretty woman say you'll stay with me...eeee" the pitch C rises to C sharp over an A major triad. This moment is so great: are we heading back to D? Is this a secondary dominant? What is this chord about? And then he goes to F sharp minor for the line "Cause I need you"! This is so brilliant! What a bizarre deceptive cadence. Listen to it...that A chord does two things: sets up a vague anticipation that we just might be going back to another D chord AND gets the song back to A major, EXCEPT IT'S EARLY AND COMPLETELY UNPREPARED! By the time the A tonic triad arrives again with "Come with me..." its character has changed completely. Somehow, we are firmly back in the land of A major...EXCEPT THE IV CHORDS ARE MINOR! The D minor chords from the first part of the bridge stay through the second section, though the A chord manages to be the comfy home. The transitional A chord before it is totally uneasy and weird sounding. Isn't it amazing what a good songwriter can do with EXACTLY the same chord in such a short span of time? And doesn't the music just sail on through those two keys? So effective.
The bridge ends with, once again, the doo-wop formula progression I, vi, IV, V, except the D chords are minor, not major. The verses, which I've ignored until now, are also based on the doo-wop progression, a sort of elongated and otherwise adjusted version. Just goes to show you that an understanding, assimilation, and mastery of materials is of primary importance in creative work, no matter how banal the materials are.
Oh, and the second part of the "bridge"? 10 measures long: 3+3+4. So unusual, but completely smooth and slick. So slick I've never noticed it until now. I need to stop, I keep finding new stuff.
Two more comments:
The verses of this song have one 2 beat measure each. Unless you're counting in two, but that doesn't make much sense. Listen for the IV chord.
John Zorn's Naked City uses this classic bass line, in D, as the foundation for their arrangement of Ornette Coleman's "Lonely Woman." Cute, right?