# Braze

Braze makes a reese's movement play in time. Current version **0.1.0**.

Two layers detuned against each other beat: harmonic k of a note at f0 swells
and fades k·f0·(r − 1) times per second, where r is the detune ratio. With a
fixed detune that rate changes with every note, so the movement of a reese
never lines up with the track. Braze adds a detuned copy of the bass and sets
its detune on every note so that the beating follows the tempo.

![Braze](assets/editor.png)

## Install on Windows

Copy `Braze.clap` into `C:\Program Files\Common Files\CLAP\`. In FL Studio 2024.1
or newer, open Options → Manage plugins, enable Verify plugins, and Find installed
plugins. Load Braze in the mixer slot of the bass. Keep the font license with
redistributed packages.

## Work with it

1. Put Braze on a single bass layer: a plain saw, or a reese whose own detune
   you have turned down.
2. Pick **Rate**: the note value one beat lasts. 1/8 at 140 BPM is 4.67 beats
   per second.
3. Pick the **harmonic** that should beat at Rate. Harmonic n beats
   n/harmonic times as fast, so all of them beat on the grid: with harmonic 4 at
   1/8, harmonic 2 beats in quarters, harmonic 8 in sixteenths, harmonic 3 in
   quarter triplets.
4. Set **Depth**. At 100 % the beating goes down to full nulls; 50–70 % keeps
   the note present.
5. Use **Phase** to move where the beat peaks. At 0° all harmonics peak
   together on every beat of the chosen harmonic's cycle.

The display shows one bar: a row per harmonic with the level it gets from the
beating, the grid at Rate, and the playhead.

Other controls:

- **Low cut** removes the copy below a frequency, so the sub does not beat.
  The sub keeps its level. Harmonics under the cut show *cut* in the display.
  Under 20 Hz the cut is off. If the chosen harmonic is under the cut on a
  note, it does not beat: the note panel says so; pick a higher harmonic.
- **Width** moves the right channel's beat against the left, up to half a
  cycle. At 100 % one side peaks while the other nulls. Check the mono sum.
- **Gate** is the input level that counts as a note.
- **Snap to semitone** rounds the detected pitch. Leave it off on detuned or
  bent notes: the copy jumps by one period of the pitch in use.

### How the detune is made

The copy is the bass read from a delay line. Its delay falls by one period of
the note per beat cycle of the chosen harmonic, which tunes the copy up by
exactly r = 1 + B/(k·f0) (B: beats per second, k: the chosen harmonic). When it
has fallen a whole period, it jumps back by one period: on a steady note both
read positions hold the same waveform, so the jump is crossfaded over 6 ms
without a seam. At a beat peak the copy lines up with the bass sample for
sample.

The low detune that low notes need is large: harmonic 1 at 1/8 and 140 BPM on
F1 (43.7 Hz) is r = 1.107, about 1.8 semitones. Higher harmonics need less:
harmonic 4 asks for about 45 cents on F1.

## Timing and limits

Detection uses about 67 ms of lookahead, reported to the host for delay
compensation. Pitch range is 30–500 Hz, one voice. The beat position comes from
the host while it plays, shifted by the lookahead so the beat stays on the
timeline. When the host is stopped, the beat runs on freely at the last tempo.

Noise, chords and the attack of a note are not periodic, so the copy's jumps
are heard there as a short blur. Before the first note, the copy assumes 55 Hz.

Braze changes the waveform in time, so pitch detection after it can be less
sure: put tracked plugins before Braze, or use MIDI. See
[Signal chain](../chain.md).