Crazy the Wikipedia link is right there and everything. Oh well! Good day!

That’s very different from what you stated early. Because “pop music” doesn’t stand for “popular music”. They are different things in the way the OP stated.

It doesn’t have to. Both can be used interchangeably but one doesn’t always necessarily mean the other. https://en.wikipedia.org/wiki/Pop_music has a really good outline on the history and why “pop music” is a sub genre of “popular music”.

Hey I smiled really well for this one.