Related Clues:

• Less popular song, often
• Single surface
• Back of a 45?
• Single bonus?
• Second half of an album
• Surprise hit, maybe
• Hit back?
• Single's opposite
• Back of a single
• 45 half
• It's usually not a 11-Across
• Flip of a hit single
• Throwaway song on a 45, usually
• Discipline, in a way
• Half of a 45 record