I played in summer groups for years on viola and various members of the clarinet family, and it was GREAT. I can still remember the joys of taking a big breath to start a phrase and realizing that you had sucked in some sort of bug. I had one terrific summer many years ago when I played in a summer wind ensemble directed by Keith Brion, who does the Sousa recreations. One of the pieces we played was “Lincolnshire Posy” by Percy Grainger, an all time favorite of mine, and the only time I ever got to play it.
Recalling those experiences gives me even more respect for sight reading harp music. I would always write in fingerings/position shifts in viola parts, and just the thought of having to make split second decisions about fingerings and pedal changes simultaneously is mind boggling.
I think there is a summer symphony somewhere in Essex County NJ, or was one recently. I never went to a rehearsal with them though, just read about it.