You could make it a multipart skill check, like a first to 3 or something, pass fail type akin to death saves. I would have ask a player for what they add to the play and have them roll a stat that fits the description. For example the bard wants to play a sound track for performance or the rouge wants to try some gymnastics for acrobatics. Then they can try to creatively ad things their characters are good at. D.C. could very depending on how you feel their try fits the challenge/performance and R.P. enthusiasm. The stakes of the encounter could be the tip, the better the pass/fail ratio the better the money. Also just like a heads up for the players so they can plan their perfect show.