Related Clues:

• Perform a cantata
• Unfaithful rodent?
• Mob turncoat
• Squeal like a stoolie
• -- -a-tat
• Sound really good
• Lab rodent
• Perform in a chorus
• Perform on 'Glee,' perhaps
• Tell the cops everything
• Maze expert
• Subway dweller
• Act the informant
• Compete on 'American Idol'
• Rizzo the Muppet, e.g