Vibrato and slide fine-tuning

Matching the synth's expression to a specific guitar tone — a subtle bluesy vibrato for a Strat, a wide whammy sweep for a metal solo — comes down to tuning a handful of numbers. alphaTab treats vibrato and slides as procedural gestures: the synth generates the wobble or the pitch sweep from parameters, not from a recorded sample. Adjust those parameters to shape how aggressive, how fast, and how far each effect travels.

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Vibrato: four flavors, two knobs each

alphaTab distinguishes four vibrato types, each with a wavelength (in MIDI ticks) and an amplitude (in semitones):

• noteWideLength / noteWideAmplitude — slow, wide vibrato applied per note. Default 240 ticks and 1 semitone.
• noteSlightLength / noteSlightAmplitude — fast, subtle vibrato applied per note. Default 360 / 0.5.
• beatWideLength / beatWideAmplitude — whammy-style wide vibrato over the whole beat. Default 480 / 2.
• beatSlightLength / beatSlightAmplitude — whammy-style subtle vibrato over the whole beat. Default 480 / 2.

Larger amplitudes push the vibrato further out of tune; shorter wavelengths make it flutter faster. 480 ticks equals one quarter note at the standard resolution.

Slides: how far and how long

Simple slides (slide-in-above, slide-in-below, slide-out-above, slide-out-below) are pitch-only ornaments — alphaTab needs to pick an offset and a slice of the note duration to run the slide over.

• simpleSlidePitchOffset — quarter-tone offset for simple slides. Default 6 (that is 1.5 semitones, i.e. three fret positions).
• simpleSlideDurationRatio — the portion of the note duration the slide occupies. Default 0.25.
• shiftSlideDurationRatio — the portion of the note used by shift and legato slides that connect two notated pitches. Default 0.5, meaning the slide starts halfway through the source note and lands on the target.

Pick-slide gestures are not tuned — alphaTab does not synthesize them.

Show it in code

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

const container = getAlphaTabContainer();
const api = new alphaTab.AlphaTabApi(container, {
  core: { file: '/scores/song.gp' },
  player: {
    playerMode: alphaTab.PlayerMode.EnabledSynthesizer,
    vibrato: {
      noteWideLength: 200,
      noteWideAmplitude: 1.5,
      noteSlightLength: 320,
      noteSlightAmplitude: 0.4,
      beatWideLength: 480,
      beatWideAmplitude: 2.5,
    },
    slide: {
      simpleSlidePitchOffset: 8,
      simpleSlideDurationRatio: 0.3,
      shiftSlideDurationRatio: 0.6,
    },
  },
});

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.

Both nested objects are mutable at runtime. Change a value on api.settings.player.vibrato and call api.updateSettings() to push it into the synth.

Where to look next

• player.vibrato and player.slide in the settings reference.
• Triplet feel (swing) — the other playback-feel knob for rhythm interpretation.
• SongBook mode — related timing knobs for songbook-style bends and dips.
• Effects and articulations — the notation side of vibrato, slides, and their cousins.