Related Clues:

• Song starter
• Emcee's remarks
• Turntable speeds
• "101" class, briefly
• "Heeeeere's Johnny!" is one
• Opening music
• Emcee's line
• "In this corner ..." begins one, briefly
• Turntable stats
• Mixing measures?: Abbr.
• Record stats
• Emcee's words
• Musical opener
• Rec. measures
• Opening remarks, briefly