Two chords in "Get Back" that hardly anyone knows about

Paul McCartney's rocking tune "Get Back" on the Let it Be album is both fun and easy to play: fun because it's a stomper of a tune that's easy to jam through, and easy because it only uses three chords (four if you're super clever, but more on that in a moment).

Because the song is in the key of A, the solo guitarist can really make good use of the low open A string as a base to keep other chord shapes anchored. Most of the song can be played on this shape:

Or if you want to get creative and impress your friends, you can use this shape:

However, here's a little trick to take your execution of this song from "A+" to "A+++" -- it's all in how you voice the two transitional chords, G and D.

The intro pounds over an A chord for three and a half measures before switching to G and D on the final two beats (this is repeated in the chorus and guitar solos as well):

At least, that's how most of the songbooks show it. In reality, if you listen closely to the recording, while George and John may indeed play a G and D chord, Paul just keeps driving away at his low A note, which results in the chords actually being G/A and D/A.

Here are two ways to voice this three chord progression, depending on which fret position you prefer:

Option two, which is the one I prefer (I don't know why, I just like playing this song higher up on the neck):

Did I mention that there might be a secret fourth chord at work here? In the chorus, when Paul sings "get back!" the band answers with a stab-and-crash chord that, in my opinion, is actually an Am7 instead of an A major chord. It's a fun chord to play if you just slide the A chord shape up to the fifth fret and punch it: