Materia (lat., substance, cause) - what other, than sound, could be the matter of music ? Of course much more: rhythmic, harmonic and melodic structures, every kind of music, even rests. Possible, but I wouldn't like to premise that as given, whose novel malleability, owed to the computer, opens so many spaces as hardly anything else in the history of music.
Moreover: no imaginations and ideas that detract from the essence. Gérard Grisey: " ... our model is sound not literature, sound not mathematics, sound not theatre, visual arts, quantum physics, geology, astrology or acupuncture." Sound as mutual matter, it shall determine everything else: constellation and process, they ought to emerge from it, equitable, because without unfolding in time even the most sounding remains silent.
How do I find what I like ?
Not at all, as I like what I find and I'm searching without knowing for what. It appears and queries me wordlessly, the talk develops within the experiment, the algorithms of transformation and organisation. Whatever in the end maybe, only just, can pass - or, simpler then, can't pass in the face of that, what already exists and whereby the new scratches along trundling - that is determined by another matter - me - and in turn not: contingent and only seemingly private are memory and decision.