Music or Noise - It is in the Ear of the Beholder
I found this report of a Lou Reed concert very interesting. It seems the debate of what constitutes music is raging in more than the classical sphere.
In the end run, I think that determination is made by the composer - he or she must write what is music to them - ignoring the pressure of audience, tutors, academia and hangers on.
Of course I also think the determination of what is music is made by the listener. So in the above situation both the musicians and the audience are right. It was music - and it was not.
Composers need to have thick skins if they are going to ignore all of the opinions that will be thrown at their music. They also need to accept the fact that there is no magical audience fairy that will ensure their music gets heard.
All you can do is write the music that sings in your soul and hope that there are others who hear the same music you do.