Progression
The vi–IV–I–V in B major
vi–IV–I–V in B major plays G#m, E, B and F# — vi, IV, I and V — across 4 chords. The same four chords as the pop loop, started on the minor vi instead — a wistful opening before the progression resolves the same way.
The chords, in order
1G#mvi
2EIV
3BI
4F#V