What composers mean when we say we're "writing" music

The usual assumption is that we're producing notation, putting notes down on paper (or, more recently, pushing pixels around a screen to emulate putting notes down on paper) just like Sebastian Bach did when he adjourned to his composing room each evening, lubricated by a bottle of brandy and powered by some costly candles (the costs of those candles alone had to have put Bach among the relatively well-off in his day.)  But that's not broad enough to describe the diversity of what we do.  Composing is also "writing" when we're committing something to a text or graphic score, or programming in some language or code, or committing something to memory.  I just read an interview with David Tudor, who also used the word writing as the verb associated with pieces he made even when they had no notation at all: perhaps some tentative oral instructions (when others were involved), sometimes circuitry diagrams or often just the circuits themselves, especially when the work was for his own use. Perhaps the whole set up of Tudor's "table of electronics", combined with his practice at playing that table (both routines and extemporaneous discoveries (perhaps the best recorded example of one of those discoveries by Tudor comes in that recording of Christian Wolff's Burdocks, when the organ Tudor was 'til then rather discretely playing suddenly roared with a wonderful and shockingly unexpected stop mixture)) adds up to a kind of writing, among the circuits, on the table, in the hands, etched in the ears/brain, etc..  But I don't think that that's quite it, either.  The aspect of writing-writing which composing-writing most critically emulates is actually the production of delay (see Duchamp: a delay in glass), the movement or shift in time which stands between writing and reading. Composition is putting music into storage for future retrieval as performance/listening.  (See also Duchamp: In Advance of the Broken Arm.)  The length of the delay is, of course, a variable, as is the presence of noise in the delay line. (See also Large Glass: dust, cracks.)