Progression · 7 songs

Axis progression (I–V–vi–IV and rotations) in real songs

Four chords, I–V–vi–IV (C–G–Am–F in C major), looped. Starting the same loop on a different chord gives its rotations: vi–IV–I–V sounds darker, IV–I–V–vi more hopeful. It's the backbone of a huge share of pop since the 1990s.

7 songs in the library use this, including music by Adele, Bob Marley & The Wailers, Bruce Springsteen and Cheap Trick. Every song has left- and right-hand piano voicings to step through on an 88-key keyboard, plus a breakdown of the harmony and structure.