Related Clues:

• Any one of the Top 40
• "Tea for Two," for one
• Sonny and Cher song, e.g.
• "Tea for Two" for two, e.g.
• Performing pair
• Musical composition for two
• Shared air
• "Up Where We Belong," for one
• Medley portion
• Carol, e.g.
• Piano piece with "primo" and "secondo" parts, e.g.
• Number divided by two?
• Something one can never do?
• Berlin number
• iTunes selection