By 'ruin' I mean turn from horrendously lame to.. the opposite of that.
So my music teacher is a bit lame she wants us to play some pretty boring songs. We're just covering past hit pop songs from the last decade or so.

I want to play something extra towards the end that we can actually rock out to
(without my teacher knowing of course)
I can only think of Hot for Teacher by Van Halen, but of course i'm not really into that (with this one anyway ;D)

Quote by tastes_of_ink

So What
Quote by Spaztikko
Imagine the part of the ballsack where occasionally old poo sticks to the pubes and hardens, and you then have to pull out, but as an amp. That's an MG.

Greatest quote of all time?

I think so...
Maybe The Somatic Defilement/Reprogrammed to Hate or even Intestinal Incubation.
Last Caress/Green Hell


For some other alternatives, how about People = Shit, or anything else by Slipknot, Lamb Of God, or Slayer. I haven't found someone who likes pop that enjoys listening to anything that heavy
Am I Evil? by Diamond Head
Necrophobic by Slayer
Black Dog by Led Zeppelin
Painkiller by Judas Priest
Flight Of Icarus by Iron Maiden
Black Rose Immortal by Opeth

Hope that some of these suggestions help.
For a joke, you should do Pink Floyd's another brick in the wall. That song has good lyrics for a school performance. Anyway hope you find an awesome song to rock out with!
Quote by Mysticwolf
For a joke, you should do Pink Floyd's another brick in the wall

Which part are you refering to part 1, part 2, part 3 or the combination of "The 'Happiest' Days of our Lives" and part 2?
Quote by Jesus_Dean
Judge: "You have been sentenced to one whole World Tour" as rhythm guitarist. You are not allowed to play any arpeggios"
Malmsteen: Your Honor, I prefer the jail sentence."
If the time is appropriate
Schools Out - Alice Cooper
And I agree with Another Brick In The Wall (Part 2)
Mercyful Fate - Nuns Have No Fun
Quote by beadhangingOne
Are you talking about those weird sphincter-spasms where it feels like there's a ghost dick in your ass for a little while and then it just disappears?