
Music · I–V–vi–IV
Four chords from one key: home (I), the dominant (V), the relative minor (vi) and the subdominant (IV). Wikipedia calls it the axis progression, after the comedy band The Axis of Awesome, whose 2008 medley showed how many songs repeat it. The same four chords started from another one, such as vi–IV–I–V, are rotations of it.
Watch for: Home, a jump to the pull of V, a step into the shadow with vi, then away to IV, and round again.