Sync effects to music

Set the tempo

Open the Beat Matcher panel. There are three ways to set the beat clock.

Type a BPM directly into the number field when you know the track's tempo or the music has none to detect. Use Tap Tempo to tap along four or more times and let Spectralite average your taps into a BPM. If the reading settles on twice or half the real tempo, the ×2 and ÷2 buttons correct the octave in one tap.

Let the detector follow the music

For live audio, turn on Auto Beat-Sync with the switch at the right end of its row. Spectralite listens to the incoming audio, finds the tempo, and trims the clock many times a second so the show tracks a band that drifts or a set that eases between tracks. The status chip reads No signal until beats reach the detector, Listening while it settles, and turns orange with Locked once it is holding tempo and phase.

Pick the audio input from the microphone button on the same row, or from Edit > Inputs > Audio. Prefer a direct feed from the mixer over a room microphone. While sync is running it drives the tempo, so the BPM field and Tap Tempo step aside; ×2 and ÷2 stay live so you can fix an octave without dropping the lock.

The detector locks tempo and beat phase but does not decide which beat is the bar's "one". Press Cue Align on a heard downbeat to set the bar and, while synced, to calibrate for microphone and output delay in the same motion. Full setup, the confidence readout, and latency compensation live in the Beat Matcher reference.

Schedule a layer on the beat grid

The simplest beat-sync needs no nodes at all. In the Timeline, each layer row carries a beat grid: one bar split into sixteen slots, four per beat, where the effect plays wherever a slot is on. This schedule lives on the timeline row, not in Layer Settings.

Click slots to build a pattern, or drag across a range. Switch a layer on for the first and third beats and clear the rest, and it hits on the two and four count against every other layer. Fill and Clear set all slots at once. Because the grid is measured in slots rather than milliseconds, the pattern keeps its place in the music whatever the tempo. The grid model is covered in Beat time.

Drive an effect from the beat clock

To make an effect move with the beat rather than just switch on and off, read the clock inside the effect. In the Node Editor, add a Time node. It has no inputs; its outputs are the beat clock in several forms:

• Beat Progress ramps 0 to 1 once every beat.
• Bar Progress ramps 0 to 1 once every bar of four beats.
• Cumulative Progress counts total beats as a continuous value that never resets, for animation that should not loop.
• Beat Index and Cumulative Beat Index count whole beats, within the bar and overall.

For a flash that fires on each beat and decays, take Beat Progress, subtract it from 1 with a Subtract node so the value starts high and falls, and feed the result into your effect's brightness before the Output node. The light snaps up on the beat and fades until the next one.

For a color that walks the wheel once per bar, feed Bar Progress into the hue input of an HSL to RGB node, wire its color through Combine Color into Output, and the effect cycles through the spectrum each bar. See Connecting nodes for how ports link, and the nodes reference for every node by category.

Shape per-layer timing

Two controls in Layer Settings change how a layer moves through time while it plays. Speed scales the layer's playback rate against the beat: 2 runs its effect twice as fast, 0.5 half as fast, without touching the master BPM. Beat offset shifts the layer's phase by a number of beats, so a small offset between two otherwise identical layers makes them chase each other.

These reshape motion but not the schedule. When a layer plays still comes from its beat grid; these only change how its effect animates within that window.