"It's not that I won't do it, I just don't think there's a particular reason to do it again, I mean I did it for the film because Tim (Burton) asked and I was happy to, to get away with it once, (but) I don't know if I could get away with it again!" SWEENEY TODD: THE DEMON BARBER OF FLEET STREET actor Johnny Depp isn't confident of his singing ability.