The Harmonic Gate

How it works

Every partial sits at some pitch. The gate compares each one against a set of “allowed” pitch classes and boosts the matches. Where those allowed classes come from depends on the mode:

• Capture — grab the pitch classes of the chord you’re currently holding and lock them in as the gate’s target. Hold a Cmaj7, hit Capture, and from then on the partials matching C–E–G–B get reinforced.
• Follow — the gate tracks whatever you play live, updating as the chord changes underneath your hands. The timbre stays glued to the harmony in real time.
• Split — a keyboard split: notes on one side run through the gate, notes on the other bypass it, so you can play gated and ungated zones at once.

The pitch-class row (C, C♯, D … B) shows and lets you set which classes are active.

The two dials

• Focus — how hard the matching partials are boosted. A little Focus is a gentle bias toward in-key harmonics; a lot makes the gate dramatic, almost vowel-like, as the out-of-key partials drop away.
• Tolerance — how strict the match is, in cents. Tight tolerance only accepts partials right on pitch; loose tolerance lets near-misses through, which matters once you’re using Stretch or just intonation and partials drift off the equal-tempered grid.

Why it’s worth knowing

On most synths, timbre and harmony are separate departments — you pick a sound, then you play notes. Here they talk to each other. Put the gate in Follow with a moderate Focus and play a progression: the sound brightens on chord tones and pulls back on the rest, so the instrument seems to know the song. It’s the synth equivalent of a player who voices to the changes.

What to Practice

• Hold a chord, hit Capture, then play around it. Hear the partials matching your chord tones pop forward.
• Switch to Follow and play a four-chord progression. The timbre should shift with each chord.
• Push Focus up for an exaggerated, formant-like version, then ease Tolerance looser if you’re using Stretch or just intonation.