Related Clues:

• Thing to hum or whistle
• Often-carried thing
• Medley portion
• Carol, e.g.
• Adjust, as a piano
• Tony-toting Tommy
• It's whistleable
• Catchy thing?
• Series of notes
• Berlin number
• iTunes selection
• ''Jingle Bells,'' for one
• Track, perhaps
• Work with notes
• Work on, as an engine