In the Beatles track P.S I Love You we hear this in action. The track is in the key of D Major, so we expect these chords: For the most part, this is what we get. However, before the track goes to ...

His fellow musicians have taken note of that fact more than a few times. Check out four of the best covers of McCartney-penned Beatles songs.

These chords are used on everything from The Beatles to Billie Eilish, and every genre of music that adopts any form of basic harmony.