Some of these sketches for pieces, my lumber, are notated conventionally, others have prose scores (or "reports" as Henry Brant called them, prose instructions from the composer to the composer to reduce anxiety in going from idea to playable score.) The less developed are just ideas, sometimes little more than a title: Meander Scar. In Praise of Wasps & Bees. Anagoge.
Here's one example from an old notebook of a work waiting for a commission:
(The title is) Two Lines. It's a long-ish piece for a medium-sized orchestra, divided in two not-quite equal parts in a fairly eccentric way, but seating ordinarily, the ensembles are not physically divided, but dovetailed. And each of the two orchestras plays a long, independent melody, each an "orchestrated unison" (with some tactical intervallic, chordal, and aggregate (including unpitched percussion) doublings). The two orchestras share a common pulse and a notationally convenient metre, but are generally independent with some distinct qualities (i.e. one has a lot of repeated tones and florid ornaments, the other has only very short and very long tones ornamented only by slow portamenti), coming together — which can mean at a unison or a consonance or some complementarity — only at major structural points (like Javanese seleh) triggered by rhythmic and tonal approchements.