Your SAT scores will suck!

[Guilmon and a shotgun]

And of course, Classical music will make you smart, but who will like you when you make them listen to it.

Other people who like that musical genre?

I don't think it's fair to judge people's intelligence on what music they listen to, it's much more accurate to simply test their general knowledge.
I am willing to accept that music amongst other media can be factors leading to deteriorating intelligence, however.

I have a friend who got straight As in his GCSEs, dispite spending his free time watching Disney channel and listening to Hannah Montana songs. Oh, and he's straight apparently in case you were wondering.