The same four chords as the "four-chord song," started on the minor vi — wistful and anthemic.
Drop vi–IV–I–V straight into the interactive looper, hit play, and hear the full sequence cycle.
Play vi–IV–I–V in the Studio →Same four chords, different starting point. Beginning on the minor vi means the listener's ear takes the vi as 'home,' colouring the whole loop with that minor mood — even though the brighter I and V are still in there.
C major, borrowing its relative minor feel: Am is the vi, F the IV, C the I and G the V. Many songs that use it feel like they're hovering between A minor and C major, which is part of its emotional pull.
The chords are identical — Am, F, C, G are the same as C, G, Am, F reordered. What changes is where the loop begins, and that single choice is enough to take the progression from upbeat to bittersweet.