Can Johnny Depp sing?

Naturally, everyone's trying to figure out whether Johnny Depp can sing based on those few seconds in the Sweeney Todd trailer where he's shown doing so. Someone on the imdb forums actually compiled an audio clip of three of the most famous Broadway Sweeney Todds and Johnny Depp singing the exact same lines. It's interesting to hear I think - Johnny's interpretation is very different. He's definitely the weakest singer, but I think his version is the creepiest. Judge for yourself here.