Possible Clues:

• Group of musicians
• Tick on official form is offensive to Vietnamese singing group
• Group of six (X, not S)
• Let it Be introduces old-time band
• Male gets offensive in Vietnam with singing group
• Jazz group
• Tick on official form is offensive in Vietnam to singing group
• Medium-sized jazz group
• 5D 17Ac playing 27Ac in arrangement of 22D, missing intro
• Half-dozen in a group