just curious, Peter, but do you think it's more difficult, for trumpet players especially, to play in Vail due to the altitude?
As a brass player I will throw in my two cents and say YES. I used to play at the Aspen festival each summer for a few years, and it always took a little time to adjust to the altitude (and attitude ). You take in the usual deep breath and feel like you aren't getting ANY air. Eventually you get used to it, and the bonus is when you go back to lower altitudes you suddenly have TONS of air! I still play a lot in Colorado (Denver area, not quite a high altitude) and the same problem exists to a lesser degree.
When I was on the road w/Woody Herman we played a gig in Aspen (around '87) and Woody got very sick from the altitude (he was not in good health at that point).