Try Carla who runs the Greenwich Village Bistro, 13 carmine st. 212 206 9777, you put a large jug on the table and if the punters like you they fill it with money. We were in for a meal ( the food is great) when the entertainment buggered off (an awful pianist) because he wasn't getting any money, we were asked to step in. We shunned the jug 'cos we were on a night off (and rather pissed, doubtful quality!) but we had our $160 dollar tab wiped off and it was great fun and we were well recieved......and we sing english trad. folk!
Also had our bar tab in Chumleys wiped off earlier in the evening ( in from 5 pm 'til 7pm rehearsing! drinking etc ($45). Although we didn't ask for the tabs to be cleared we would have cheerfully done it for nothing, when we offered to pay they said it was ok .
At least a free meal at Carla's gaff would be worth it!
regards
Peter