Progression
The vi–IV–I–V in E major
vi–IV–I–V in E major plays C#m, A, E and B — 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
1C#mvi
2AIV
3EI
4BV