Related Clues:

• Peter, Paul and Mary, e.g.
• Peter, Paul & Mary, e.g.
• Group of three
• Exec
• Kingston, e.g.
• 17-Across
• Quartet when one's out sick
• Quarter deck?
• It's short of a quartet
• See 70-Across
• Quartet minus one
• Destiny's Child, e.g.
• Something to follow
• Lounge group, maybe
• Kingston, for one