Beat Tracker
Beat Tracker estimates tempo and maintains a beat clock from live audio or incoming beat events. It does not change the timeline until its outputs are connected to the desired controls.
Inputs and setup
Source selects Audio, Events, or Audio + Events. Audio arrives at In, with channels summed to mono. In Events mode, send pulses to Beat: integers and floats are interpreted as beat numbers, while impulses and other values mean an unnumbered beat. Events per beat accommodates subdivisions, such as 24 pulses per beat for MIDI clock.
For audio, select Band, set Gate (dB) above background noise and constrain Min BPM / Max BPM with Limit BPM range. Transport tempo hint helps choose between half-time and double-time interpretations. Clock filter, Whitening, Lookahead (ms) and Offset (ms) refine detection and output timing.
Outputs and performance controls
- Tempo is the estimated BPM; connect it to an interval’s Tempo inlet to drive tempo.
- Speed is a playback-rate multiplier that corrects phase as well as tempo; use it with a synchronizer or Speed inlet instead when following position matters.
- Phase and Bar phase run from 0 towards 1; Beat index counts beats and Next beat (s) predicts the next beat.
- Beat, Downbeat and Onset emit timing events. Confidence, Locked and Valid let the patch decide whether to trust the result.
Use Tap to establish tempo while unlocked or reset phase while locked; Resync declares the downbeat without changing tempo. x2 and /2 correct tempo-octave mistakes. Nudge -/+ correct alignment. Hold freezes tempo but still follows phase; Follow off freezes the clock and stops analysis. Set Beats per bar to the intended meter.
Sparse, ambiguous or silent audio can lose lock. Monitor Confidence and Valid and provide a suitable manual fallback rather than assuming continuous reliable tracking. See Analysis for onset and other audio descriptors.