Related Clues:

• Often-carried thing
• Ad music
• Medley portion
• Carol, e.g.
• Adjust, as a piano
• Tony-toting Tommy
• It's whistleable
• Catchy thing?
• Berlin number
• iTunes selection
• ''Jingle Bells,'' for one
• Track, perhaps
• Work with notes
• Work on, as an engine
• Get ready to play, say