The "four-chord song" — the progression behind an astonishing number of pop hits.
Drop I–V–vi–IV straight into the interactive looper, hit play, and hear the full sequence cycle.
Play I–V–vi–IV in the Studio →Because so many popular songs use these exact four chords in this order that comedians have famously played dozens of hits back-to-back over the single looping progression. It's one of the most reliably catchy sequences in Western pop.
vi (Am here) is the relative minor — it shares most of its notes with the tonic but sounds sadder. Dropping to it after the bright I and V adds a moment of introspection before the IV lifts back toward home, which is what gives the loop its bittersweet character.
They use the exact same four chords — only the starting point changes. I-V-vi-IV opens on the bright, resolved tonic; vi-IV-I-V opens on the minor vi, so it feels more wistful even though the chords are identical.