You know the Beatles’ song “Hard Day’s Night”? Sure you do.

You know that odd, sudden, slighly off chord that starts it? Sure you do.

You know what chord that is? Sure you don’t. Oddly, it turns out that nobody really knows what chord that is. How is that possible? I have no clue. Don’t the remaining Beatles have some insight?

A doctor at Dalhousie University in Canada tried to figure it out, but could never get it right. He thinks he’s finally figured it out. Apparently, there’s more than just the Fab Five playing on the recording. He thinks there’s a piano note in there as well.

That’s a load off my mind.