Possible Clues:

• Giving the singer help with a number in return
• Singer takes up most of the seat
• Showbiz egotist
• Very keen to do a turn as a singer
• Battle, e.g.
• Title given to Madonna and Aretha Franklin
• Keen to make a come-back in the opera ?
• Demanding superstar
• Literally, 'goddess'
• Egoistical, demanding sort