At the moment I have no idea and the festival is rapidly approaching.
I'm going to have to do some research and see if my pain-addled brain can come up with something... far too often I let festivals slip past without marking them, and I can't keep doing so as I feel really guilty when I do!
It will be nothing huge or demanding, as I'm assuming that my arm will still be hurting (and if I plan something taking that into account and it turns out that my arm is better, than I've lost nothing and can always add stuff "ad-lib"). I'll have to have a think and see what I can come up with.