Tracker

Contour does not turn your playing into MIDI. A note-on with a single velocity number cannot hold a scoop into a note, a swell in the middle of one, or the wobble of vibrato. So Contour skips notes altogether. It measures your pitch and your loudness 125 times a second, hands those readings to the synth, and the synth moves smoothly between them. Slide up a fifth and the synth slides with you, because there is no note event for the gesture to collapse into.

One line at a time

Contour is monophonic. It follows a single pitch, so give it a single voice or one instrument playing one note at a time: singing, whistling, saxophone, flute, a bowed string, a monophonic synth line. Chords, a strummed guitar, or two players bleeding into the same mic give it several pitches to choose between, and it will keep picking one and changing its mind.

What it hears

Pitch	Continuous, in cents — not snapped to a semitone
Loudness	The whole shape of a note, not one velocity at its start
Attack	How hard a note starts — tongued, plucked, a consonant

Those three drive the synth. Contour also measures brightness, breath noise, and the rate and depth of your vibrato as you play. Nothing is routed from them yet.

How close it gets

Two stages share the work. A small neural network guesses your pitch from a short window of audio, then a conventional pitch detector refines that guess into a much finer reading. On a clean, steady tone the result lands inside a cent, and it holds within a few cents through vibrato and glides. Those figures come from test tones whose pitch was known in advance. A real player in a real room is harder, so read them as the good case rather than a promise.

Readings per second	125
Tracking delay	~24 ms, before your audio buffer
Pitch resolution	Under a cent on a steady tone

That short window is where the 24 ms comes from. Pitch is a property of a waveform over time, so there is nothing to measure in a single instant; the tracker has to hear a little of a note before it can commit to an answer. Your buffer size adds to that — see setup for the total.

Reading the trace

The pitch trace plots what you are playing against time, in semitones, with a spectrogram of the incoming audio below it.

Pitch trace and spectrogram panel — Pitch trace above, spectrogram below. Idle here — no input signal.

A held note draws a flat line. Bends and glides draw continuous slopes rather than a staircase of steps. Vibrato shows up as a fine, regular ripple riding on the line. Where Contour is unsure — breath, consonants, silence — the trace thins out or drops away instead of jumping to a wrong pitch. That is the fastest way to tell a tracking problem from a synth problem: if the trace is wrong, no amount of knob-turning downstream will fix it.

Getting clean tracking

The tracker only sounds as good as what reaches it. A close mic, one sound source, and nothing bleeding back in from monitors do most of the work. If notes still misfire after that, the fix is in the synth panel's TRACKING section rather than in mic technique.

Next: the synth panel.