Yes, many heavy metal bands will use their bass or guitar players as back up singers and many of the successful bands have members that can operate on all the instruments. It's kind of like when sports icons make it to the pros, they are all around musically gifted and that's why Iron Maiden is one of the greatest heavy metal bands to ever exist.

He's very good, although I wouldn't put him in the Bruce Dickinson or Ronny James Dio category...