Rap? Isn't that a synonym for "Knock"?

"She was in the house by herself and someone "rapped" loudly on the door."

Right? That's rap?

Tonight I had a dear TEENAGER over at my house babysitting the kids. Now, this "teenager" is very mature for eighteen years. I love her and she's about the only person I trust to watch my kids. That trust is what allowed her to walk out of my house vs. being KICKED OUT!

Let me start from the beginning:
I got home and we are chatting about her concert she went to Monday. The group was called "Little Wayne" or something, a group I have never heard. My teenager says, "They are a rap group. Do you know what rap is?"

MY. JAW. DROPPED.

Hellllewwww.... I grew up with MC Hammer baby. Or maybe you remember the song "Baby Got Back"??? Or, OH, I know... Vanilla ICE! Hellow! Do I KNOW RAP??

Me: "I take the Turbo Kickboxing class because it's my only safe way to listen to rap without people thinking I'm trying to relive my youth. Teenager, you just made me feel REEEELLLYYY Old."
Teenager: "Oh gosh, I"m sorry (laughing). I have to tell my mom what rap is so I just..."
M: "Well, I do listen to Red Hot Chili Peppers a lot... that's more my scene." Notice I threw in a word that might relate to her: "scene"?
T: "Oh yeah, I've heard of them..." said hesitantly.
M: "Hmmmm... I guess I'll test the waters here... Depeche Mode?"
T: "Who's that?"
M: "New order?"
T: "Nope."
M: "Both are alternative/modern. Like the Cure."
T: "Oh wait! I think I've heard of the Cure."
M: "Dave Matthews Band"
T: "I HAVE heard of them."

I'm starting to lose confidence with her use of the word "of". That implies she's heard their name in passing but that she doesn't know their songs.

Me: "Teenager, sweetie, what DO you like?"
Teenager: "Oh I like country."

Well that explains it all....