Beat Sync

Beat sync locks your visual animations to the tempo of the music. Instead of reacting to volume (that’s audio reactivity), beat sync creates rhythmic, repeating patterns that stay perfectly in time with the beat grid.

Tip

For the full architectural picture of how the beat clock and modulation system interact, see the Audio & Beat concept and the Modulation System concept. This guide is the hands-on version.

Setting the BPM

The BPM BPM beat Beats per minute — the tempo of the music. Can be set manually, tapped in, detected automatically, or synced from another app via Ableton Link. section is a dockable panel (default position: left column). You have five ways to set tempo:

• Fixed — type a BPM value directly. Reliable, drifts only if the track tempo drifts.
• Tap — click the Tap button in rhythm with the music. Lightbridge averages up to eight recent taps; if you pause for more than three seconds the history resets so you can try again cleanly.
• Auto Sync — Lightbridge listens to the audio and detects the tempo automatically. Best on material with strong, regular beats.
• Ableton Link Ableton Link beat A networked tempo-sync protocol. Any Link-capable app on the same network shares tempo and phase with Lightbridge automatically — no configuration on either side. Learn more → — if you’re running Ableton Live (or any Link-enabled app) on the same network, Lightbridge matches its tempo and phase automatically. No config on either side.
• MIDI Clock In — slave the tempo to incoming MIDI Clock from a DAW (Ableton without Link, Logic, FL), a CDJ, a drum machine, or anything that transmits 24 PPQN clock. Enable in the BPM panel; the jitter readout shows lock quality. Mutually exclusive with Ableton Link. See the MIDI guide for setup.

When you change the BPM by any means, the beat clock’s phase is preserved — beat-synced modulations never “jump” to a different position on a tempo change.

Note

Tap Tempo sets BPM only. It doesn’t reset which beat you’re on. If you need to align phase to a specific downbeat, use the separate Resync button — it’s the tap-tempo-and-Resolume approach.

For live use you can drag the Resync button onto any pad in your controller panel (or right-click → “Learn MIDI binding…”). Pressing the bound pad fires a resync instantly — perfect for an APC pad or footswitch when you need to slam visuals back to the downbeat without taking your hands off the controller.

Adding a beat-synced modulation

Any parameter can be driven by a beat-locked modulation. The workflow:

1. Right-click the parameter’s slider and choose Add LFO LFO modulation A steady repeating cycle, driven by time. Runs free in Hertz or locks to the beat grid. mod (or Add Beat mod for the raw beat counter — see below).
2. In the modulation panel that opens, set the source config. For LFO, switch the rate from Hertz to a beat division beat division beat Beats per cycle. 1 = once per beat, 4 = once per bar. Higher values = slower motion. (1 = quarter note, 4 = bar, 0.5 = eighth note, and so on).
3. Pick a response curve — see the next section.
4. Set the output range to the part of the parameter range you want the modulation to swing across.

The slider now shows a live overlay of the modulated value. Drag the range handles on the slider during a performance to tighten or open the swing.

LFO vs Beat sources

There are two ways to get a beat-synced signal:

• LFO source with a beat division set. The LFO locks to the beat grid but has its own phase offset, so you can drift it relative to the downbeat. Use loop for a sawtooth cycle, bounce for a triangle.
• Beat source. Reads the beat counter directly with no phase offset. Always perfectly in sync, no drift possible. Use when you want rhythmic behaviour that is locked hard to the grid with nothing to tune.

In practice: LFO gives you more flexibility, Beat gives you more certainty. Start with LFO for most things; reach for Beat when you want absolute grid-lock.

Beat divisions

The beat division controls how many beats per cycle. The modulation panel exposes the full set:

Division	Meaning (in 4/4)
0.125	Eighth-triplet — 3 cycles per beat
0.25	Sixteenth note — 4 per beat
0.5	Eighth note — 2 per beat
1	Quarter note — 1 per beat
2	Half bar
4	One bar
8	Two bars
16	Four bars
32	One phrase
64	Two phrases
128	Four phrases

Higher values give you slow, structural movement (palette hue drift across a song); lower values give you fast, rhythmic movement (strobe-like or drum-synced pulses).

Response curves — how the signal is shaped

Unlike classic LFOs where you pick a shape like sine, triangle, or square, Lightbridge produces a linear ramp from every oscillator and then shapes it with a response curve. The curve is what gives you “sine-like,” “square-like,” “bouncing,” “stepped,” or any other non-linear response. This one mechanism is far more flexible than a fixed shape list.

Some useful starting points:

• For a smooth sinusoidal feel → use the sCurve preset.
• For a square wave / on-off behaviour → use the gate or step preset.
• For stepped / quantised movement → use stairs4 or stairs8.
• For punchy overshoots → use bounce.
• For a held plateau with ramps → use shelf.
• For pure saw (default) → use linear.

See the Modulation Curves reference for a visual preview of every preset. You can also edit the curve directly in the modulation panel — add control points, drag handles, right-click for options.

Tip

Want a classic synth shape? Lightbridge’s LFO outputs a linear ramp; the waveshaping comes from the response curve you pick. For a sine-like feel, use sCurve. For a square wave (on/off), use gate. For a sawtooth, the default linear curve already gives you that. Any classic shape can be built from the curve presets.

Audio reactivity vs beat sync

	Audio Reactivity	Beat Sync
Driven by	Volume of frequency bands	Tempo clock
Feel	Organic, follows dynamics	Rhythmic, metronomic
Best for	Pulsing, energy response	Cycling colours, sweeping, timed transitions
Use together	Bind Scale to Kick	Bind Hue to an LFO with beatDiv = 16 and sCurve

The most powerful setups use both: audio reactivity for energy-responsive movement on some parameters, beat sync for rhythmic patterns on others. The current mod panel UI allows one modulation per parameter — so instead of stacking on one param, assign audio and beat modulations to different params and let the combined motion read as layered. Example: Scale on the kick for punch, Hue on a 16-bar LFO for slow palette rotation.

Related

• Audio & Beat concept — the architectural view of the beat pipeline.
• The Modulation System — signal flow, audio reactivity, direction, range mapping.
• Modulation Curves reference — every preset curve with a shape preview.
• Audio Reactivity guide — the complementary workflow.