Ananova:

Johnny Depp is reportedly to have a voice test before composer Stephen Sondheim will allow the actor to star in musical Sweeney Todd.

The composer fears his vocals may be too rock 'n' roll to play the murderous barber.

According to IOL.com a spokesman for Sondheim says: "He wants to make sure that all versions of his works are the best possible."

Tim Burton, will direct the movie, due out in 2008.