Team Green
Wow!, even though I probably won't be around in 50 unless someone invents a major youth serum in the next few years I would hope there would remain a fringe element still wanting to hear real musicians play.

I can see it already ... "live at Wembly stadium:  Intel i7 and Siri!" 

tobiaslindahl
I think music is dying in that sense, it already is in a way. The devotion and time required to play at a high level is not something a lot of people will want to put into it going forward I think. So less people learning to actually play an instrument, therefore the demand for instruments will diminish. Instruments will be more and more computer based (we are already there) with "press a key get a song" type stuff. AI as mentioned above will play into this I am sure. 
 
This is how future instruments will look:

 
 

 
I fully expect to see the musical interface to the mind, where AI will tap into your intelligence, your emotions, your "life energy" and generate music and you do absolutely nothing but sit and concentrate, if even that's necessary, followed by accolades and applause to your musical genius.  The rationalizations are already being invented every day.  "Why must I be limited to physical training when expressing my art?  This is just another tool, yeah...a tool that gets to the core of where art lives, close to the soul, the heart, pure emotional energy without the corruption of translation into biological components and crude archaic instruments." 
 
Something like that...
 
 

I realize that I am leaving out several genre's of music when I say this, but the most important element of music is still the human voice and I don't see that changing.  

I guess it depends on who's human voice we are talking about  Not mine.

The future of music is Bruno Mars!

there is no future in music