Beat Kitchen Harmonic Synth

A music theory aware additive synth built on the harmonic series — now passes live input as an effect using a Harmonic Vocoder to leverage the full power of the engine

BKS Harmonic is an additive synthesizer that builds sound from individual overtones — then gives you tools to shape, scan and filter them by musical harmony.

Audio Unit v3 (AUv3): load it as a plugin inside AUM, GarageBand, Cubasis, Loopy Pro and any AUv3 host, or run it standalone. Automation and presets work as you would expect.

FOLD INSTEAD OF FILTER The partials display shows every overtone in your sound. Sweep the fold slider and upper partials fold below the fundamental, redistributing the energy across harmonic layers. Not a filter. Not a waveshaper.

AN ARPEGGIATOR FOR HARMONICS The Overtone Scan steps a spotlight through individual partials with triangle, saw or random patterns. Lock it to a scale and it only visits partials that belong to it.

THE TIMBRE FOLLOWS THE HARMONY The Harmonic Gate reinforces partials whose pitch class matches your chord and suppresses the rest. Capture a chord, follow incoming MIDI, split the keyboard so your left hand drives the gate, or pick the notes by hand on the gate's own keys.

SCULPT Draw the level and pan of every partial. Slide the whole curve up the grid as a formant, and lock individual partials in place while the rest moves.

THE HARMONIC VOCODER Pass live input or a loaded sample through the synth as an effect. Your sound travels through a bank of tuned peaking bells rather than being replaced by filtered noise: open the Air and the source stays dry, tighten it and the bands resonate into it, reaching a comb at the narrowest settings. Key Track is the mode switch — on, the bands follow the keyboard and it plays as an instrument; off, it is a fixed filter you can sweep. Aimed at a sample, the bands track that sample's spectrum as it evolves. It shares one Blend control with the oscillators, level-matched, so you can crossfade between additive synthesis and vocoding without the loudness moving.

MODULATION A full mod matrix with a cog on almost every control, so the synth's own engine can drive nearly any parameter in the interface — including the display itself. Sources include velocity, envelopes, LFOs, the number of notes you are holding, the number of oscillators sounding, the synth's own output level, and Atmo, a shape driven by 84 years of barometric weather data. The ranges run from sub-atomic frequencies to earth weather patterns — audio rate down to cycles that span years. BKS Harmonic now incorporates data from the popular Beat Kitchen Weather Sonification Project. Learn more on our website.

THE SCOPE A stereoscope, oscilloscope, spectrum and a live per-partial display. Glow takes the trace from a hard line to a diffuse gas-tube bloom, Colour sets the hue for every view, and all five scope controls are modulation targets.

ALSO Every control has a tooltip — hover or long-press anything to see what it does. Presets work offline and remember which modules you had open. A harmony wheel follows what you play.

One purchase, every update: you get every new feature and every fix as the synth keeps growing.

Made by Beat Kitchen, a music production and live teaching community for artists.