Related Clues:

• Wax unit?
• 70's 'in' spot
• Ump's call
• Music to do the hustle to
• Dance party
• Summer music
• Beat-based music
• Word that can follow the ends of 17-, 26-, 43- and 58-Across
• Nightclub
• 'I Love Lucy' star
• Word with hall or fever
• Donna Summer's forte
• See 25-Down
• Chain's end, sometimes
• '70s ''in'' spot