Related Clues:

• Together (with ''in'')
• High male voice
• In __ (together)
• Type of singing
• Tiny Tim, for one
• Something funny to sing in
• Vocal style of 10-/25-Down, at times
• Perfect agreement
• Artificial high voice
• Full agreement
• Complete harmony
• A trio may sing in it
• ...and so is this
• Register for Tiny Tim
• Doo-wop song's high voice