can't believe some people here suggested to vandalise the machine. I would have thought the simple answer would be for the bar tender to talk to his boss about the noise and how the OP reacted and let the boss/owner deal with it. If I were the operator and a staff member told me to turn it down I'd probably say no too, if the owner/boss of the bar told me to turn it down I'd find out why and do it if needed.