I know I've seen several fics in which Clark has a bad singing voice. Is that canon?
Happy
According to the folc wiki page "Clark never sang in the series. Dean Cain is reportedly unable to carry a tune, and this has translated into several fanfic stories."
http://folc.wikia.com/wiki/Clark_can%27t_sing
Woo! A use for the wiki at last:
http://folc.wikia.com/wiki/Clark_Kent#Fanon ETA: Ninja'd! XD
At least your link works, Queen! I don't know what happened to mine. :p