POD #1: Elvis is born stillborn, instead of his twin brother, Jesse. His brother turns out not to have the musical talent as his brother, and leads a fairly normal life.
POD #2: Paul McCartney never joins up with the Quarrymen, and the various members of what would have been the Beatles never get beyonf maybe one number one hit in the UK and never become very noted in the US.
So, how does popular culture evolve because of this?