Settings Reference

The exhaustive companion to Settings. Every setting the app stores, what it is called, what it accepts, and what happens when you give it something it does not accept.

Settings are opened from the gear in the top bar — there is no menu entry. They are stored per browser origin under the localStorage key rmt:settings:v1. Every change applies immediately: there is no OK/Apply/Cancel, and the app's Undo/Redo does not cover settings. The only way back is a reset.

Every setting, in one table

Five sections, one per panel tab. A tab's id is also its section name.

Path	Type	Default	Range / values	Control
appearance.themeId	string	'classic-orange'	classic-orange, slate-cyan, mono-light, high-contrast	Theme dropdown
appearance.overrides	object	{}	sparse map of token → hex	The 15 color pickers
appearance.note.heightWU	number	22	8 – 60, step 1	Note height
appearance.note.borderPxAtZoom1	number	1	0 – 6, step 0.5	Border thickness
appearance.note.roundedCornerPxAtZoom1	number	6	0 – 20, step 1	Corner radius
arrows.enabled	boolean	true	—	Show note arrows
arrows.mode	string	'reciprocal'	reciprocal, independent	Arrow mode
arrows.up	{n, d, label}	{n: 2, d: 1, label: null}	positive integers; 1/16 ≤ n/d ≤ 16; n/d ≠ 1	Up interval + quick-pick chips
arrows.down	{n, d, label}	{n: 1, d: 2, label: null}	same; derived from up in reciprocal mode	Down interval — shown in independent mode only
audio.masterVolume	number	1	0 – 1, step 0.01	Master volume (and the transport slider)
audio.defaultInstrument	string	'sine-wave'	the nine instrument names	Default instrument
audio.reverb.enabled	boolean	true	—	Enable reverb
audio.reverb.roomSize	number	0.5	0 – 1, step 0.01	Room size
audio.reverb.decaySec	number	1.8	0.1 – 12, step 0.1	Decay
audio.reverb.damping	number	0.5	0 – 1, step 0.01	Damping
audio.reverb.preDelayMs	number	20	0 – 200, step 1	Pre-delay
audio.reverb.wet	number	0.25	0 – 1, step 0.01	Reverb amount
audio.stereo.enabled	boolean	false	—	Spread notes by pitch
audio.stereo.width	number	0.6	0 – 1, step 0.01	Amount
audio.limiter.enabled	boolean	true	—	Limiter
library.iconSizePx	number	56	32 – 96, step 4	Icon size
library.showCents	boolean	true	—	Show cents
library.layoutVersion	number	2	any number	no UI, no consumer
scale.x	number	1	clamped into scale.limits.xMin … xMax	Horizontal (time)
scale.y	number	1	clamped into scale.limits.yMin … yMax	Vertical (pitch)
scale.limits.xMin	number	0.3	0.001 – 1000	Horizontal range
scale.limits.xMax	number	2	0.001 – 1000	Horizontal range
scale.limits.yMin	number	0.3	0.001 – 1000	Vertical range
scale.limits.yMax	number	5	0.001 – 1000	Vertical range

Defaults reproduce the app's pre-settings behaviour exactly, with one deliberate exception: reverb now defaults on. Stereo defaults off; the limiter defaults on.

Appearance

Control	Type	Range	Default	Hint shown
Theme	dropdown	4 presets	Classic Orange	"Presets apply a full color set and note geometry; pick one, then customize below."
Note height	slider, N wu	8 – 60, step 1	22 wu	"Bar thickness in world units."
Border thickness	slider, N px	0 – 6, step 0.5	1 px	—
Corner radius	slider, N px	0 – 20, step 1	6 px	—
Reset colors to theme	button	—	—	Disabled while you have no overrides

Then fifteen color pickers (a native swatch plus an uppercase hex readout), in three groups.

Choosing a preset discards your color overrides — and re-seeds the geometry sliders

The theme dropdown clears appearance.overrides before it applies the preset, with no confirmation, and writes the preset's declared note geometry into appearance.note — picking High Contrast lands border 2 px / corner 4 px, overwriting whatever the sliders held. Only the Reset colors to theme button asks first (and it, unlike the dropdown, leaves geometry alone).

Theme tokens

The fifteen tokens with a picker, and their value in each preset:

Group	Picker label	Token	Classic Orange	Slate Cyan	Mono Light	High Contrast
Interface	Accent	accent	#ffa800	#38bdf8	#d17400	#ffd400
Interface	Background	bg	#151525	#0b1120	#f5f5f0	#000000
Interface	Panel surface	surface	#151525	#111a2e	#ffffff	#0a0a0a
Interface	Panel border	surfaceBorder	#3a3a4a	#26334d	#cfcfc7	#ffffff
Interface	Text	textPrimary	#ffffff	#e6f0ff	#1a1a1a	#ffffff
Interface	Muted text	textSecondary	#aaaaaa	#8fa3c0	#666660	#dddddd
Interface	Active / delete	danger	#ff0000	#f43f5e	#c62828	#ff2d2d
Workspace	Note border	noteBorder	#636363	#5a6a85	#9a9a92	#ffffff
Workspace	Playhead	playhead	#ffa800	#38bdf8	#d17400	#ffd400
Workspace	Measure bars	measureBar	#ffffff	#cbd5e1	#333333	#ffffff
Workspace	Selection ring	selectionRing	#ffffff	#38bdf8	#d17400	#ffd400
Workspace	Hover ring	hoverRing	#ffffff	#cbd5e1	#333333	#ffffff
Dependency highlights	Frequency	depFrequency	#ff8000	#fb923c	#e06600	#ff8000
Dependency highlights	Start time	depStartTime	#00ffff	#22d3ee	#0088aa	#00ffff
Dependency highlights	Duration	depDuration	#9d00ff	#a78bfa	#7a2fd0	#c46bff

Each token is also published as a CSS custom property on <html>: --rmt-accent, --rmt-bg, --rmt-surface, --rmt-surface-border, --rmt-text-primary, --rmt-text-secondary, --rmt-danger, --rmt-note-border, --rmt-playhead, --rmt-measure-bar, --rmt-selection-ring, --rmt-hover-ring, --rmt-dep-frequency, --rmt-dep-start-time, --rmt-dep-duration, plus --rmt-accent-text, --rmt-note-default-saturation, and the RGB triplets --rmt-accent-rgb, --rmt-bg-rgb, --rmt-surface-rgb, --rmt-danger-rgb for rgba(var(--x), α) forms — --rmt-surface-rgb is what drives every 0.88-alpha panel background.

Every preset also carries three values with no picker: accentText, noteDefaultSaturation and newNoteColorMode. noteDefaultSaturation is consumed — published as --rmt-note-default-saturation, it sets the saturation of the random colour a new note gets — but you can only change it by picking a different preset. accentText and newNoteColorMode are declared and read by nothing.

What each workspace picker reaches:

• Selection ring colours the ring around a selected note, the selection wash, the group (multi-select) ring, and the outline of a selected BaseNote or measure triangle. The rubber-band marquee rectangle follows the Accent picker, not this one.
• Hover ring colours the hover ring on notes, the BaseNote and measure triangles.
• Frequency / Start time / Duration (Dependency highlights) colour both the dependency rings and the dependency link lines.
• Text (textPrimary) also recolours all on-note glyph text — fraction labels, the word "silence", the octave arrows, and the BaseNote fraction.
• Panel surface drives the translucent panel backgrounds via rgba(var(--rmt-surface-rgb), 0.88).

Selecting a preset also applies its declared note geometry, re-seeding the three sliders — High Contrast lands border 2 px / corner 4 px. The sliders remain the way to fine-tune afterwards, and Reset colors to theme never touches geometry.

Arrows

Control	Type	Range / options	Default	Hint shown
Show note arrows	checkbox	—	on	"Turn the ▲/▼ interval arrows on notes off entirely."
Arrow mode	dropdown	Reciprocal (up ×r, down ÷r), Independent up/down	Reciprocal	—
Up interval (ratio)	two number fields n / d + a live cents readout	positive integers; 1/16 ≤ n/d ≤ 16; ≠ 1	2 / 1 (1200.0¢)	"Down applies the reciprocal in reciprocal mode."
Quick pick	six chips	see below	—	—

Quick-pick chips and the cents they show:

Chip	Ratio	Cents
Octave 2/1	2/1	1200.0¢
Fifth 3/2	3/2	702.0¢
Fourth 4/3	4/3	498.0¢
Major 3rd 5/4	5/4	386.3¢
Whole tone 9/8	9/8	203.9¢
Syntonic comma 81/80	81/80	21.5¢

Rules:

• In reciprocal mode, arrows.down is re-derived as d/n on every write of arrows.up. Set up to 3/2 and down becomes 2/3.
• An invalid ratio heals to your previous value, per field: a bad numerator or denominator restores just that field from the ratio you had, while a wholly out-of-range ratio (17/1, 1/20) or one equal to 1 (3/3) reverts wholesale. Only a corrupt store loaded fresh — with no previous value to heal from — falls back to the default 2/1. The number fields carry a min of 1 but no max, so the browser lets you type 100; the store is what corrects it, and it visibly rewrites the fields with the healed value.
• Nothing forbids an "up" ratio below 1. Set arrows.up to 1/2 and ▲ transposes downward.
• Unchecking Show note arrows dims the ratio editor and the chips but leaves them editable. The values take effect when you switch arrows back on.

In Independent up/down mode a Down interval (ratio) row renders below the up editor — the same two number fields and live cents readout, hinted "Only used in independent mode". (It is hidden in reciprocal mode, where down auto-derives.)

Audio

Control	Type	Range	Default	Hint shown
Master volume	slider, %	0 – 1, step 0.01	100%	—
Default instrument	dropdown	nine names	sine-wave	—
Room / Reverb
Enable reverb	checkbox	—	on	"Adds spatial ambience to the output."
Room size	slider	0 – 1, step 0.01	0.5	—
Decay	slider, N.N s	0.1 – 12, step 0.1	1.8 s	—
Damping	slider	0 – 1, step 0.01	0.5	—
Pre-delay	slider, N ms	0 – 200, step 1	20 ms	—
Reverb amount	slider, %	0 – 1, step 0.01	25%	"How much reverb is mixed in on top of the dry signal (0% = dry, 100% = fully wet)."
Stereo width
Spread notes by pitch	checkbox	—	off	"Places low notes toward the left speaker and high notes toward the right, as if seated at the instrument. Off = centered (mono-position)."
Amount	slider, %	0 – 1, step 0.01	60%	—
Master
Limiter	checkbox	—	on	"Gentle output limiting to avoid clipping."

The tab's footer reads: "Reverb, stereo and the limiter apply live during playback."

Instrument names

sine-wave, square-wave, sawtooth-wave, triangle-wave, organ, vibraphone, fm-epiano, piano, violin.

audio.defaultInstrument is the fallback, not an override: a note uses it only when neither it nor anything up its frequency chain pins an instrument. See instrument inheritance.

Behaviour worth knowing

• Master volume is two-way bound to the transport volume slider in the top bar. Dragging either moves the other. The transport slider only persists on release; while you drag it, it emits a live echo the panel follows.
• Room size, Decay and Damping re-render the reverb impulse response, debounced by 250 ms. Reverb amount, pre-delay and the enable toggle are live parameters.
• Stereo width is applied when a note is scheduled, so it changes newly-started voices, not ones already sounding.
• The limiter is a peak catcher: −6 dB threshold, knee 6, ratio 12, attack 0.003 s, release 0.25 s.

Library

Control	Type	Range	Default	Hint shown
Icon size	slider, N px	32 – 96, step 4	56 px	—
Show cents	checkbox	—	on	"Display cents alongside ratios in the module library."

Both apply live to the module bar.

library.layoutVersion is stored and validated but has no control and no consumer. It is not a user setting.

Scale

This tab and the small accent dot at the bottom-left of the screen are two views of the same two numbers. Touch either and the other follows.

Control	Type	Range	Default	Hint shown
Horizontal (time)	slider + editable number	spans the horizontal limits	1	"How far apart notes sit along the time axis."
Vertical (pitch)	slider + editable number	spans the vertical limits	1	"How far apart octaves sit along the frequency axis."
Slider limits
Horizontal range	two number boxes, min – max	each 0.001 – 1000	0.3 – 2	—
Vertical range	two number boxes, min – max	each 0.001 – 1000	0.3 – 5	—

Rules:

• Scale persists across reloads. You come back at the density you left.
• The number box is how you land on an exact value. It clamps into the current limits — widen the limits first to go further.
• The slider's detent is derived from its range: about a fiftieth of the span, snapped to a 1/2/5 ladder. At the default limits that is 0.02 horizontally and 0.1 vertically — both keep exactly 1.0 reachable by dragging.
• Editing the limits retunes both this tab's sliders and the bottom-left widget's sliders, live.
• If you type a min that is not below the max, the field you just edited wins and the other gives way by a factor of ten, rather than the edit being rejected.
• Narrowing the limits pulls an out-of-range scale value back in with them.

Resets

Every tab ends with two buttons, at the bottom of its scroll flow.

Button	Resets	Confirm button
Reset this tab	the section of the same name as the tab	Yes, Reset Tab
Reset all	all five sections	Yes, Reset All
Reset colors to theme (Appearance only)	appearance.overrides only — geometry is untouched	Yes, Reset Colors

All three ask first. The confirmation dialog focuses Cancel, and is dismissed by Cancel, by Escape, or by clicking outside it.

Settings changes are not undoable — the app's Undo/Redo covers the module, not the settings. A reset is the only way back.

The stored envelope

Everything lives in one localStorage key.

Key	rmt:settings:v1
Schema version	1
Scope	per browser origin

{
  "version": 1,
  "appearance": {
    "themeId": "classic-orange",
    "overrides": {},
    "note": { "heightWU": 22, "borderPxAtZoom1": 1, "roundedCornerPxAtZoom1": 6 }
  },
  "arrows": {
    "enabled": true,
    "mode": "reciprocal",
    "up":   { "n": 2, "d": 1, "label": null },
    "down": { "n": 1, "d": 2, "label": null }
  },
  "audio": {
    "masterVolume": 1,
    "defaultInstrument": "sine-wave",
    "reverb": { "enabled": true, "roomSize": 0.5, "decaySec": 1.8, "damping": 0.5, "preDelayMs": 20, "wet": 0.25 },
    "stereo": { "enabled": false, "width": 0.6 },
    "limiter": { "enabled": true }
  },
  "library": { "iconSizePx": 56, "showCents": true, "layoutVersion": 2 },
  "scale": {
    "x": 1,
    "y": 1,
    "limits": { "xMin": 0.3, "xMax": 2, "yMin": 0.3, "yMax": 5 }
  }
}

Paths are dot-delimited: arrows.up, audio.reverb.wet, appearance.themeId, scale.limits.

How a bad value is handled

The whole tree is re-validated on every single write, then persisted. That is what keeps derived invariants (the reciprocal down) true and what makes a hand-edited storage entry safe. validateSettings(raw, prev) takes an optional second parameter — the pre-edit tree — and the store passes it on every set/setSection, which is what lets an invalid arrow ratio heal to the value you previously had instead of a schema default. Load and migrate paths pass no prev. The envelope, key and version are unchanged.

Situation	Result
Key missing	Defaults
Corrupt JSON	Warn to the console, then defaults
A number out of range	Clamped into range
A field of the wrong type	Replaced by its default
An invalid arrow ratio	Healed to your previous ratio (per-field); only a fresh load with nothing to heal from falls back to 2/1
An inverted scale range (min ≥ max)	That axis's limits fall back to their defaults wholesale
Scale limits narrowed around a far-off value	The limits are validated first, then the value is clamped into them
localStorage full, or private mode	Non-fatal: settings work for the session but are not saved

There is no migration code. v1 is the first and only version — the versioned envelope is scaffolding for a future one. Partial or corrupt stored settings are healed by validation, not by migration.

What is not a setting

• No import/export of settings, no settings file, no cloud or account sync.
• No per-module settings — settings belong to the browser, not to the composition.
• No undo for a settings change.
• No OS light/dark detection. mono-light is a preset you pick by hand; there is no prefers-color-scheme handling.
• No custom named themes. Four presets plus a flat override map is the whole story.
• The panel's position is not persisted across reloads (it does survive close → reopen).
• The instrument dropdown is a fixed list. A newly registered instrument would not appear in it automatically.

See also

• Settings — the walkthrough
• Themes & Appearance
• Transposing with Arrows
• Audio & Reverb
• Module JSON Schema