There are lots of discussions going on for some time about whether a streaming music service like Spotify, MOG, Rhapsody, Grooveshark, etc. The discussions go around whether it's possible to support the music industry paying fees like $0.30 per track listened, or even much less (source).
Things become a little bit more complicated when you get to classical music. On popular music, tracks are much more comparable: an album with 12 tracks usually takes 12 times more work to produce than a single with one track. So paying by the track is not too bad. However, when you get to classical music, it's hard to compare the cost to produce a single track for something like Morton Feldman's Piano and String Quartet that has one single "movement" that is 65-77 minutes long (depending on the rendition). On the other hand, you get things like operas that have tracks that are just a 30-second recitative between movements, or, if you want to go to the extreme, I have to mention John Cage's 4'33" (and yes, there are recordings of it).
So maybe you can claim that on average is good, but is average enough? Will this just create incentives for music to all be based on many short tracks and it will become less than it is today? Will we have similar quality reduction than the one generated by the famous "loudness war" that happened with CDs? Spotify doesn't think so, according to their blog post:
But I guess it's their job to believe that music streaming services are here to actually save the music industry from the doom that digital music is causing it.
My opinion is actually that music cannot be ever treated as a "one solution fits all" for how you consume it, how you interact with it, and how you pay for it. The more the simplifying effect of mass marketing of technologies reaches all our experiences, the less quality we will end up getting from our diverse experience.
Whatever happens, no artistic expression will ever disappear. And I believe in technology. I think that we will probably go through a period that there will be a drop of quality to what we get exposed to, but I think that's just necessary to get the technology to stabilize and people to understand the actual economy of it. Then there should be another expansion, which will bring back quality and diversity with the right price.
It's just like when music recording started. You first had just live performance. And the sound quality was great! Then came the first recordings and everything was convenient, but terrible sound quality. Slowly then sound quality was improved with new technologies to a point, at the peak of vinyl, for you to get amazing depth of sound if you wanted to pay for the equipment.
Then we started a new wave of quality reduction in the name of convenience. We'll have to ride this wave, and on the other side of it I believe we will find a world where we can enjoy more of the things we like.