4 Chord Songs video (I V VI IV) - The Axis of Awesome

Four chords Song with the chord progression (I  V  Am  IV), a common use of the scale tone chords.

 - look at the sheet with Get Back at the top, in the middle is the 4-chord main chord progression for I'm Yours by Jason Mraz. It's the very same chord progression, in fact, that song is in this video. Try playing it.

Axis of Awesome - 4 Chord songs