I've followed this with much interest, and i note several references to accidents in music.
How do those 'accidents' occur?
By experimentation. How do we experiment?
By stepping outside what we already know.
So i'm not agreed with the principle of accidents, and the resulting (or not) continuation of a new path of 'creativity' based on a standalone coincidence, unconnected to anything else.
It's my opinion that accidents don't actually occur, rather a new creative 'node' or 'notion' comes to life as the result of an opening of the creative synapses to 'allow' a stream of new thought/emotion to come to life. Every note, chord, percussive sound, impact, hum, etc. has the potential to take many new paths in new directions outside of our current known experience. We know when stuff doesn't work, and as Gugliemo referred to, my view of the importance of objectivity holds true. But it's also the case that my view is tempered by my notion of what is acceptable or not. e.g. I prefer Wagner to Schnietke. Why? Because Wagner 'fits' my life/creation/analytical/emotion/experience model better. It doesn't mean i question the validity of Schnetke, merely make a personal preference, according to what i 'accept' under the very general title, Music.
Nor does experience (or not) take away from the musical potential. I think it's important to separate the creative 'notion' encapsulated by BOTH thought and emotion, and the practical means to bring that notion to life.
Consider the young composer who can hear a complete symphony with unfettered clarity in his thought/emotion centre. What prevents him from 'transmitting' that complete notion into reality is not only a lack of practical compositional and orchestration experience as we understand it, but quite possibly the limitations of the instruments themselves. Sound, timbre, reflection of change of tone by dynamic may separately or collectively detract from that 'pure' symphonic picture he sees and feels.
So the discussion of separating the composer and performer is already one stage on from the real question, (in my opinion) instead the real question should be:
'What is the notion in the composer's thought/emotion centre?'
We hear an extrapolation of that performed by ourselves and /or others, but by necessity, it is already a 'tainted' version of the pure reality created in the first place.
Regards to you all, and thanks William for starting such an interesting discussion!
Alex.