Of course, I've heard James 'Spike' Marsters sing too.
Live.
(there's also a stained glass window in a church in Cardiff that bears an amazing resemblance to him. Being as it's meant to be Jesus I find that ridiculously amusing)
James Marsden was Corny Collins in Hairspray, which was made of much awesome. At least let me play you him singing 'That's Amore' from the Enchanted soundtrack!