Possible Clues:

• It might involve a bouncing ball
• Amateur singing to recorded music, perhaps in a pub
• Activity where you may take a shot at 'Hit Me With Your Best Shot' and then take a shot
• Japanese music
• Attendees adding to number in such bars?
• Singing event for fun
• Bar activity with request slips
• Singing entertainment
• Singing entertainment of Japanese origin
• Singing to pre-recorded tune