Related Clues:

• Operatic piece
• 'Say Say Say,' say
• Love song, at times
• Any Sonny and Cher song
• Performance that takes a second
• ''Dueling Banjos,'' for one
• Four-handed piano tune
• ''Say Say Say,'' say
• The Human League's 'Don't You Want Me,' e.g.
• Something one can never do
• Performance that takes a second?
• ''Baby, It's Cold Outside,'' e.g.
• Number one can’t do
• Sonny and Cher, e.g.
• Piece marked "piano, four hands," obviously