[Membership 2 Pro] which plugins to use to accomodate orchestra

Dear WPMUdev,
I would like to supply the members of my orchestra with a closed part of the website where they can find music. That is not the difficult part I presume: I create one type in membership (and perhaps a second for donors) and give them access to a closed page with short links to their own parts.
But I would also give them the opportunity to enlist (or decline) in participation of a concert (or other event). Every tuesday, we practice and normally you are there. But sometimes you wan't to let people know you are not coming. So default is available, and the option is to decline. But there are events, every player has to sign in.
Do you have suggestions how to combine these requests?