DARN YOU YOU TUBE AND THE LAND DOWN UNDER! thou hast ruind pop muic for me Fo' Eva! I weep bitter bitter tears! What has been seen can not be un-seen! Now all I hear is the chords!
Aussies have always been corrupting our children. When I was a kid it was AD/DC, and today it is Justin Bieber.
They've also likely shifted all the songs into the same keys to make it work. Basic harmony theory dictates that a lot of pop songs are going to have similar chord patterns. Most of them are just I-IV-V.