Progression
The I–IV–V in Eb major
I–IV–V in Eb major plays Eb, Ab and Bb — I, IV and V — across 4 chords. The three-chord song — folk, country and early rock's whole harmonic vocabulary in one loop.
The chords, in order
1EbI
2AbIV
3BbV
4EbI
I–IV–V in Eb major plays Eb, Ab and Bb — I, IV and V — across 4 chords. The three-chord song — folk, country and early rock's whole harmonic vocabulary in one loop.