Multi-bar rests

Collapse runs of empty (or rest-only) bars into a single multi-bar rest glyph with a count above it — the traditional big-band notation for a horn section that sits out for eight bars, or a sight-reader's cue for how long an educational score's empty stretch runs. Ensemble parts get shorter, sight-readers get a clearer count, and the layout algorithm has fewer bars to squeeze onto each row.

Collapse consecutive empty bars into a multi-bar rest

Score-wide vs cherry-picking

Two fields on score.stylesheet control the feature:

• multiTrackMultiBarRest — a boolean. When true and multiple tracks are rendered together, subsequent bars that are empty on every rendered track collapse into one multi-bar rest.
• perTrackMultiBarRest — a Set<number> of track indexes. Add a track's index to opt it in. When it is null (default), the score-wide rules apply as-is; when it holds indexes, only those tracks participate in multi-bar-rest collapsing.

The two work together. In a full-band render, multiTrackMultiBarRest = true collapses empty regions across the band. If you're rendering a subset — a solo transcription of the bass line — populate perTrackMultiBarRest with the track index to get the same behavior on a single-track render.

Related empty-staff controls

If your goal is not to compress rests but to hide a track when it has nothing to say for a while, two adjacent flags do that instead:

• hideEmptyStaves — hides staves whose entire content in a system is empty.
• hideEmptyStavesInFirstSystem — extends the same behavior to the first system, which normally stays visible so the reader sees every part at least once.

These are independent from the multi-bar-rest flags and can be combined.

Show it in code

import * as alphaTab from '@coderline/alphatab';

const container = getAlphaTabContainer();
const api = new alphaTab.AlphaTabApi(container, {
  core: { file: '/scores/song.gp' },
});

api.scoreLoaded.on((score) => {
  // Enable it band-wide:
  score.stylesheet.multiTrackMultiBarRest = true;

  // Or cherry-pick which tracks participate:
  score.stylesheet.perTrackMultiBarRest = new Set(
    score.tracks.filter((t) => t.name.includes('Bass')).map((t) => t.index)
  );

  api.render();
});

getAlphaTabContainer() is a placeholder for the platform-specific step of obtaining the render target — a <div> on Web, an AlphaTab control on .NET, or an AlphaTabView on Android. Every other line runs unchanged on all three runtimes.

Where to look next

• Bracket extend mode — how the accolade bracket handles hidden or collapsed staves.
• Track name policies — labeling behavior around hidden staves.
• Repeats and structural elements — the counted glyph pairs with repeat structures on ensemble parts.
• multiTrackMultiBarRest and perTrackMultiBarRest on the RenderStylesheet reference.
• scoreLoaded and render — the API surface used above.