Cornelius Cardew quotes:

A Composer who hears sounds will try to find a notation for sounds. One who has ideas will find one that expresses his ideas, leaving their interpretation free, in confidence that his ideas have been accurately and concisely notated.

Bear in mind that parts of the score may be devoid of direct musical relevance.

The notation is more important than the sound. Not the exactitude and success with which a notation notates a sound; but the musicalness of the notation in its notating.

The score must govern the music. It must have authority, and not merely be an arbitrary jumping-off point for improvisation.