I think there will always be a place for live performances of music. Nothing else comes close. I was skeptical when Fantom Events broadcast (narrowcast) live performances from the Met to movie theaters nationwide last summer.
I was pleasantly surprised that those concerts, at least out here, were capacity crowds ... and that the one-time events actually went into repeat performances. Okay, it's not live music but it was 100% affirmation that there is a public that wants to see live music, opera, symphony concerts. (I don't think those would fly so well.)
If its a relief: when I shop for music CDs I want to handle them, I want to hold the package in my hand, read the jacket, listen to cuts on listening stations. I don't do that on the internet ... I go to the store.
My wife does the same with books ... and she reads a lot of them.
Instruments: same thing, I go to the store I handle them, decide if what is available is better than what I have and work a deal (always seems to be in their favor) to take my old gear in trade.
Sheet music, on the other hand, I get by one of three means.
1. Download from the Internet. Both purchased and free public domain just because stores just don't sell sheet music any more.
2. Transcribe by ear ... time consuming, but often the only means available to get out of print titles.
3. Get it from the morgue ... friends with filing cabinets of unused, ready to discard music. Latest acquisition was from Canada.
Getting on your movie kick ... that I see being a problem for two very sound reasons. Ticket and concession prices and the crack cleaning crews they have at the theater. I don't want to spend $50 for a family of three to see a film and sit in the lap of sticky popcorn encrusted luxury. (Oops, last weekend we saw two films)
... but I didn't like it. :-)