<score-live-chord-analysis>

This component displays the chord named from the selected player’s currently held MIDI notes. Optional alternate interpretations appear as secondary text beneath the main symbol, not as commands. Applications that need past transitions can retain timestamped Headless tracker updates.

@webmusic/score/analyze/element<score-live-chord-analysis>

Parameters

playerBorrow held notes, state and note events from one selected player; no score input is read.densityType and spacing defaults for this single surface.schemeExplicit palette for this surface.spellingPitch-name spelling; automatic uses the available key context.alternatesShow or hide static alternate readings below the live chord symbol.stability-msDelay the chord-change event until a displayed name remains stable; 0 emits immediately.

<score-player>

srcURL of a MIDI / MusicXML / MXL / ABC file, loaded through the sibling @webmusic/score/io capability.formatForces the parser when the extension is missing or lies. Only read while src is being loaded.sound-fontURL template with a {midi} placeholder — one sample per note. A value without {midi}, or any value once .sound is assigned, is ignored.volumeNative player volume, applied live and clamped to >= 0; ignored once .volume is assigned. Inert in Rack/controller modes; use score-rack-control for Rack mixing.rateNative playback speed, applied live. Non-finite or non-positive values fall back to 1; ignored once .rate is assigned. Rack members keep their own rates; explicit .rate writes also reach a borrowed controller.panNative stereo pan, applied live and clamped to [-1, 1]; ignored once .pan is assigned. Inert in Rack/controller modes.loopNative whole-piece looping, applied live. Ignored once .loop is assigned; inert in Rack/controller modes.time-controlHow much of the clock to show: simple is the elapsed time, full adds the total. Changes in place, without remounting the transport.volume-controlAdd a volume control to the chrome, as a horizontal fader or a rotary knob. Moves the same knob the volume attribute sets; needs the element to own its engine, so it is inert in .rack and .controller mode.

<score-live-chord-analysis></score-live-chord-analysis>

Import

<script type="module">
  import {defineScorePlayerElement} from '@webmusic/score/play/element';
  import {defineLiveChordAnalysisElement} from '@webmusic/score/analyze/element';
  defineScorePlayerElement();
  defineLiveChordAnalysisElement();
</script>

<score-player id="piece" src="/midi/Arabesque%20No.1.mid"></score-player>
<score-live-chord-analysis player="#piece"></score-live-chord-analysis>

The live demo pairs this component with one <score-player> using the same /midi/Arabesque%20No.1.mid source as the other Score Analyze demos. Parameters configures those two elements; Copy includes their markup and Reset restores their original attributes and connection. For optional supporting views, see Compose a performance. defineLiveChordAnalysisElement(tag?) is idempotent and SSR-safe; defineAllAnalysisElements() registers the Analyze family from the same entry.

Behavior and lifetime

The nameplate and .chord update immediately as held notes change. When a single note or another set has no defensible chord name, the main reading shows its actual pitch names; .chord remains undefined and no chord-change event is invented. The symbol, voicing and alternate rows keep their height through rests and note changes. Alternate readings, when shown, are noninteractive text below the primary chord. Display configuration stays in the external Parameters section. webscore:chordchange waits for a stable, nonempty chord symbol; a changed note set or reset cancels an outstanding notification. The component has no history lane, score seek, keyboard, staff, fretboard, tabs or settings strip.

This tag uses the selected player’s held notes and note/state events. When available, the player’s .playback shared source supplies current activity and subsequent updates; the event path remains a compatibility fallback. It has no score-loading attributes. A native snapshot initializes current held notes, while a structural event-only source begins with incoming notes. Without note input it waits. Late or replaced targets are rebound.

The selector must match exactly one target in the current Document or ShadowRoot. Invalid or ambiguous matches remain unbound. Native single-score player mode supplies complete initial data/state; Rack/controller modes do not promise that snapshot. Disconnect cancels owned work, releases subscriptions/observation and destroys presenters, while the borrowed player keeps its own lifetime.

API

Attributes

Attribute	Values / default	Behavior
`player`	selector, absent	Exactly one source in the component’s Document or ShadowRoot; borrow held notes, state and note events.
`density`	`comfortable` / `compact`, `comfortable`	Type and spacing defaults for this surface.
`scheme`	`light` / `dark`, inherited	Pin this surface’s palette; removing it follows the page.
`spelling`	`auto` / `sharp` / `flat`, `auto`	Pitch-name spelling from the available key context or an explicit preference.
`alternates`	`show` / `hide`, `show`	Include or omit noninteractive alternate readings below the primary symbol.
`stability-ms`	milliseconds `0`–`1000`, `80`	Delay a nonempty `webscore:chordchange` until the displayed symbol remains stable; `0` emits immediately. Invalid values use `80`. Does not delay the nameplate.

Unknown display values fall back to the documented default. This fixed component has no type, show, shell, range or tuning control; configure sibling pitch views on their own tags.

Properties

Property	Type	Behavior
`.density`	`comfortable \| compact`	Reflected density.
`.scheme`	`light \| dark \| undefined`	Reflected palette; undefined removes the override.
`.spelling`	`auto \| sharp \| flat`	Reflected pitch spelling.
`.chord`	read-only `string \| undefined`	Named chord symbol; undefined for silence or a note set without a defensible chord name.
`.stabilityMs`	`number`	Reflected notification delay in milliseconds.

LiveChordAnalysisElement is exported from @webmusic/score/analyze/element. Inherited .selection and .analysis are undefined on this note-only component. Inherited selectRegion() and clearSelection() have no effect on this tag; assigning inherited .score does not turn it into a score lane. There are no public playback methods.

Events

All emitted events bubble and are composed.

Event	Detail	Trigger
`webscore:chordchange`	`{chord, midis}`	The displayed nonempty chord remains unchanged for `stability-ms`; silence, reset, source replacement and changed notes cancel pending notification.

Accessibility

The nameplate exposes the current chord or literal pitch names, pitches and optional alternate readings as text. Its main and secondary rows retain their size as the interpretation changes, with horizontal scrolling for unusually long readings. It has no alternate-choice button, slider or transport command. Automatic motion respects reduced-motion preference on moving surfaces; display controls remain outside the component.

Styling

The component uses light DOM. Its block host fills the available width and can shrink in flex/grid layouts; application CSS can override its layout. Set public tokens on this host or any ancestor. The component does not install host-local theme defaults that mask inherited values.

One outer surface owns background, border, padding and radius. The inner musical presenter stays unframed, so translucent backgrounds are painted once. Use --wm-component-background, --wm-component-border (a complete CSS border), --wm-component-radius and --wm-component-padding; the corresponding --wm-workbench-surface-* tokens provide a specific override. By default it has a neutral surface, a 1px border and .6rem padding on all sides, matching the player. Its light/dark colors follow the inherited scheme or the explicit scheme attribute. Set the component border and padding to 0 and its background to transparent for a frameless composition. --wm-surface, --wm-foreground, --wm-accent, --wm-border (a color) and --wm-control-radius supply shared palette and control defaults. Existing --wm-analysis-* and --wm-harmony-* palette overrides remain supported.

score-live-chord-analysis {
  --wm-component-background: transparent;
  --wm-component-border: 1px solid #94a3b8;
  --wm-component-radius: .75rem;
  --wm-foreground: #0f172a;
  --wm-accent: #7c3aed;
  --wm-accent-foreground: #fff;
}

Nameplate text follows --wm-foreground; --wm-harmony-foreground can override only this presenter family. Alternate names are static secondary text and wrap within the available width.

Stable part tokens are root on the direct child wrapper, presentation, surface, content, index, and nameplate and symbol. Use selectors such as score-live-chord-analysis [part~="surface"] in application CSS. These are light-DOM hooks, not Shadow DOM ::part() selectors; private .wui-* classes are not an API. The same hooks remain available after configuration changes and reconnects.

The harmony presenter and workbench presenter own the complete token references. No header, tabs, dock controls or sibling pitch views are embedded in this component.