COMPOSER INSTRUMENTS

Composer instruments

Status: Intent, for LIVE-003. It describes the code on main as of 2026-10-05 and adds no instrument. The three instruments are exactly the visuals a Current may name, RISE_CURRENT_VISUALS = ['still', 'attractor', 'genesis'] (src/core/rise-current.js:23). The fixtures are in src/live/fixtures/explanations.js and tested in explanations.test.js.

A Composer answer is one sealed Current (decision). Each passage names one instrument. The answer names one of the nine themes. The model supplies no number, colour, CSS or renderer setting. What each theme draws with is RISE's fixed table, RISE_CURRENT_THEMES (rise-current.js:122-131).

The rule underneath all three

The words and the voice carry the explanation. The instruments carry atmosphere. None of the three draws the subject: an attractor behind a passage about weather is not Lorenz's attractor, and a genesis composition behind a forest is not a forest. A reader who sees nothing, hears nothing, or has imagery held still loses no fact. That is what makes it safe for a model to choose, and safe for a reader to switch off. So "explanatory versus atmospheric" means two things here. still is the explanatory default: it leaves the passage to the words. The two moving instruments add a mood to a passage the words already explain.

The three

	still	attractor	genesis
What it is	No field. The reading stands on its theme's page colour	A strange-attractor filament that turns slowly (AttractorField, src/visuals/attractor.js)	A Klee-like composition that grows, rests, then dissolves into the next (KleeField, src/visuals/klee-field.js)
Purpose	Attention on the words: definitions, numbers, caveats, conclusions	Motion, energy, process, things in flux	Growth, emergence, accumulation, slow change
Role	Explanatory default	Atmospheric	Atmospheric
What the theme sets	Page colours only	System, palette and form, e.g. cobalt → Thomas, blue, mirror. With no theme, the renderer's defaults	Preset, e.g. jade → gravitational
Timing	Nothing moves	Continuous	About 28 s to grow, 9 s at rest, a 1.6 s crossfade (klee-field.js:22-24)
Reader control in the embed	None. "Calmer" or "more vibrant" on a still passage is refused, because there is nothing to adjust	The only adjustable instrument: intensity 0.4 to 0.75, default 0.65 (ATTRACTOR_VISUAL_MANIFEST), through "more vibrant / make it calmer"	None
Reduced motion	—	Holds one still of the same field. An intensity change applies at once, without the 320 ms ease	Holds one finished composition and does not dissolve
Photosensitivity mode	—	Not read. It never flashes	Holds still
Flashing	Never	Never	Never. The change between compositions is a 1.6 s crossfade
Assistive technology	The text is the content	Canvas is aria-hidden	Canvas is aria-hidden
Needs	Nothing	A 2D canvas	A 2D canvas

Every Current lowers to a continuous presentation, so none of the three ever reaches the photosensitivity notice or the flash path. See the embed safety record (docs/experiments/EMBED-SAFETY-2026-10-05.md, SyberLabs/RISE#409), which also covers what reaches the ChatGPT frame and what does not.

Limits shared by all three

• One instrument per passage, chosen from a closed list. The instrument changes only at a passage boundary.
• One theme per answer. Whatever a passage says does not change the colours.
• At most 16 passages (RISE_CURRENT_LIMITS). The answer's visual rhythm is therefore coarse by design.
• The instrument says what a passage is like, as the model's guide puts it (src/live/guide/). It is never evidence, and it never stands in for a word.

Three explanations, three demands

Fixture	Theme	still	attractor	genesis	Demand
BLACK_HOLES_CURRENT (src/test/sealed-current.js)	none (RISE ink)	3	2	1	Mixed: a still frame for each fact, motion for mergers and waves, growth for the first image
FOREST_AFTER_FIRE	jade	3	0	3	Contemplative: mostly still, growth where something grows, nothing that turns
WEATHER_CHAOS	cobalt	1	5	0	Dynamic: the attractor carries it, and only the limit it arrives at is still

The tests check, for each: it is admitted by validateRiseCurrent and by the Worker's rise_present, it compiles to a continuous Session, and its demand matches the table. The two new ones are written the way the guide asks a model to write: a short first passage, a theme, no Dive notes (a Composer presentation offers no Dive) and no sources (a Current carries none). The black-hole Current keeps the Dive notes it has always carried. The validator still accepts them, and the embed does not show them.

Neural, Flame and Gallery stay out

Neural is a specimen and score visual in the catalog with current.supported: false (src/core/visual-catalog.js:71-80). It is not in RISE_CURRENT_VISUALS, and the validator refuses it. Flame and Gallery are refused the same way. The fixture tests assert all three refusals. Admitting any of them is separate work, and each of these steps is an owner decision:

1. Change the sealed contract (RISE_CURRENT_VISUALS is pinned by FND-006, so this is a v2 Current or an explicit contract change).
2. Give it a fixed per-theme mapping beside RISE_CURRENT_THEMES.
3. Define its reduced-motion and photosensitivity behaviour, and test that it never flashes.
4. Add Worker admission tests and witness it in the embed on the exact release.

For the Reader lane's engine catalog (B3)

When the engine catalog gains its composer flag, its Composer view must equal RISE_CURRENT_VISUALS: still, attractor and genesis, in that order and nothing else. The test runs in that direction, catalog checked against the Current constants and never the reverse (Consolidated Reader §5). A catalog that lists a fourth Composer engine fails the test. It does not widen what a model may send.

Not decided here

• Whether the model's guide should say what each instrument is for, as the Purpose row does. Today it says only that visual "says what a segment is like". Changing it changes what host models are told, and it should be tried in a host session before it lands.
• Whether still should ever take a quiet field of its own. That would change the presentation, not the contract, and belongs with LIVE-004.

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Published from docs/plans/COMPOSER-INSTRUMENTS.md. Edits made here are overwritten on the next push to main.