Ulrikke
No more frogs
That said, I was NOT convinced during his song in OMWF. I'll give him props; it must be difficult to sing with a non-native accent that you are also trying to temper according to the character's inclinations and environment. Even so, I felt like his true American accent slipped out a lot during Rest in Peace.
I never really thought about that, but then I always think that people sound more or less neutral when singing (I can only think of a few examples of singers who let their accent show very obviously). Or just American apparently.
I do seem to have a vague memory of James saying somewhere that Joss wanted him to sing with an accent, but James specifically said that he wouldn't, because people don't do that. So I guess it was a deliberate choice. Or I could just be making it up.