Is orchestral music dead, or has it just changed a bit over time?
If you mean Classical music...then yeah it's losing it's older fans and not enough young people are taking their place. But that's more the case here than Europe, they have such an established tradition that young people seem to incorporate their love for classical into the more modern music. Orchestras there seem to be doing fine.
When CD's were first released Classical music had a huge surge of popularity, I know I bought hundreds of CD"s myself, they are on average far better recordings than most rock music. Digital seems to have suited them to a tee, and young people who only wanted a few songs can now buy them. I prefer complete works but as long as some people support the genre that's good enough for me.