Songsmith

Sometimes Microsoft manages to make something useful. Usually unintentionally, but still. Microsoft Songsmith seems to be one such thing. It works by adding instruments when you sing to it. So, people have entered the vocals for some hits and the results are... completely wacky. Check these out:

The Clash : The Clash - Should I Stay Or Should I Go
Billy Idol : White Wedding
Metallica: Enter Sandman
Motörhead: Ace of Spades
Queen: We Will Rock You

And many others you can find in Youtube.