Or would they rate it mature. 

Does the n-word make a game mature?

Would they put in old school rap songs that no one likes?

It would be removed.Guitar hero III had a song from the Dead Kennedy's .In the lyrics the n-word was present and it was replaced by "brothers"

That would be funny if a rap song said brothers all the time

Reminds me of :
"Were Brothers were happy and were singing and were colored"

Naggers!

They can always edit out the profanity... That's what they do on the radio, even though a little part of me dies every time I hear an edited word.

If it were a hip hop game it would more than likely be rated M and it would probably hve the "n" word in it

Even though Creep is easily Radioheads worst song, I hate it when the edited version is played replacing "fucking" with "very"

All games have censored the word "Fuck", every single time. Rock Band and GHWT have both said "Whore", but neither game has said "Bitch" for some reason (although that seems bass-ackwards in my honest opinion), and GH:A said "ass" a couple times... RB, GHIII, GH:M and GH:WT have all said "Hell". "Shit" has been censored in Rock Band 2, but "Damn" is in RB2. "Cunt" is also censored in Rock Band 2. If Skeezing is considered swearing, it's in GHWT. Also, The word "Porno" (extended and abridged) is in both, if you consider that swearing...

As for the "N Word", where ctk referred to the Dead Kennedys, that was a cover, so they could've just decided to tell the cover artist to do that... And sometimes when the Dead Kennedys played that song live, they also said "Brothers", so, that doesn't really count...

So a Quick Chart:
Word Censored?
Ass - No
Bastard - ???
Bitch - Yes
Cunt - Yes
Damn - No
Fuck - Yes
Hell - No
Shit - Yes
Nigger - ???
Porn - No
Whore - No

There ya go... If anyone wants to fill me in on the ??? words, or wones that I missed, let me know...