"why is Mark worried about it?" part of that music belongs to Mark and the rest of Creed as well. Mark, Scott P, Brian and Brett plyed a large part in CREED and maybe they don't want their music played by JUST anybody. I know Mr. Stapp is on the credits but, I just find it hard to believe he was the creative entity. If he were the sole creator wouldn't The Great Devide have been better? All I'm saying is maybe Mark doesn't want Creeds music played by a back up band.
