My trio, Ezeduzit, has been part of various fundraising concerts from time to time. Haven't had a bad time yet; we're well treated and the audiences are great.
What I'm thinking of doing is organizing a small roster of performers and actively seeking out fundraising groups with the idea of doing a concert for a portion of the gate.
In other words, I guess this would be a quasi-commercial endeavour.
Has any of you ever been involved in something like this, and if so, is there any advice you'd care to give? What might be a fair split - 50/50?