Lets reset the question. You asked earlier when was the best time to visit. And the majority agreed it was the Fall, especially Sept. and you sort of agreed to that. The question of the music venues would change the recommendations. Most of the music/entertain activity is during the summer months with a couple of programs extending into early September. Most of the resorts are in a change over mode from summer activities winter activities in the months of Sept and Oct. So you will find most of those area fairly dead but offering great value for lodging and meals.

And don't afraid of August. As I posted earlier brutally hot is a personal perception. The temperatures averages for the past three years for Aug in Denver are --

High Ave Low
2013 94 78 52
2012 95 87 49
2011 97 75 55

Not a day over a hundred and a light jacket with some of the lows might be nice. IMO, hardly brutally hot. So draw your own conclusions.

And if you come from the hot humid southeast, that 90* and arid humidity feels like 70!! Don't forget the sunscreen no matter when you come!!
We have actually found early August to be a high season of travel to Denver based on the airport, and fullness of flights--people finishing up their summer before school starts back home.
With the exception of "mud season", Colorado is a great place to visit at any time IMO.

Hey - if it does get "brutally hot" - stay overnight at altitude - where it's cooler.

Travelbroadcaster:
No matter the childish fixation on an adjective, the upshot here is that autumn is a wonderful time of year to visit Colorado. Temperatures are cooler, skies are clear, if you catch the aspens changing, it's gorgeous. But,90 never feels like 70, no matter where you're from, and the plains ARE hot in the summer (sometimes too hot to do much outdoors). My point (reiterated more than once) is that summer in the mountains is much better than summer in the plains, so far as outdoor activities are concerned. My personal favorite is early fall.

Sylvia - are you a grade school teacher?

Well, I agree with sylvia that Denver can be very hot in the summer. We live here, and I hate hot weather, so am super-sensitive, though. It's MUCH better than humid heat elsewhere.

If you like music festivals, Aspen is the place. It is so gorgeous there. Room rates can be high, so you need to shop around and plan in advance. We like The Gant condo-hotel.

We were in Aspen last June and loved it, as always. It can be rainy in the early summer, but we had good weather.

July and August in Aspen are glorious.