draft: false
Name: Fifths
short-description: A quantizer/sequencer that can create harmony and nimbly traverse the circle of fifths in attempts to make jazz
Language: C++ (Pico SDK + ComputerCard)
Creator: Dune Desormeaux
Version: 1.1
Status: Released
demo-link: https://youtu.be/xdUCDX7FmOA
date-created: 2025-05-24
date-updated: 2026-07-04

tags:
  - quantiser
  - sequencer
  - harmony
  - cv
  - generative

summary: |
  Fifths quantizes incoming or generated CV to keys arranged around the circle of fifths and outputs both
  a quantized note and an ambiguous third harmony voice. It can run from external clock (Pulse In 1) or internal
  tap-tempo clock, and can loop or write incoming material depending on switch state/toggles. Loop length is set by X,
  key center is selected by Main (or CV In 2), and CV In 1 transposes up to two octaves. Pulse outputs provide
  an internal clock pulse plus a probabilistic sequence pulse stream.

panel:
  inputs:
    - id: AudioIn1
      name: CV/Audio Source
      description: Main signal to be sampled/quantized (or internal random source when unpatched)
    - id: AudioIn2
      name: VCA CV
      description: Optional VCA/modulation control for input scaling
    - id: CVIn1
      name: Transpose CV
      description: Adds up to roughly two octaves of transpose before quantization
    - id: CVIn2
      name: Key CV
      description: Selects key index around the circle of fifths
    - id: PulseIn1
      name: External Clock
      description: Advances quantizer/sequencer on rising edge when connected
    - id: PulseIn2
      name: Loop Toggle
      description: Toggles loop/write behavior
  outputs:
    - id: AudioOut1
      name: Key Monitor Output
      description: Main knob-centered monitoring signal
    - id: AudioOut2
      name: VCA Output
      description: Scaled input/random signal used as quantizer source
    - id: CVOut1
      name: Quantized Note
      description: Primary quantized pitch output (MIDI note mapped to CV)
    - id: CVOut2
      name: Third Harmony
      description: Harmonic third (major/minor context-sensitive) from quantized note
    - id: PulseOut1
      name: Internal Clock Pulse
      description: Gate pulse at internal quarter-note timing
    - id: PulseOut2
      name: Sequence Pulse
      description: Pulse stream from probabilistic/looped pulse sequencer

controls:
  knobs:
    - when: { z: any }
      main:
        name: Key Center
        description: Selects key center index when CV In 2 is not connected
      x:
        name: Loop Length
        description: Sets quantizer/sequencer loop length from 1 to 12 steps
      y:
        name: VCA Att
        description: Controls input scaling; can be replaced by Audio In 2 control
    - when: { z: down, gesture: hold }
      x:
        name: Pulse Duration
        description: Sets pulse output gate length
      y:
        name: Pulse Probability Threshold
        description: Sets probability threshold for sequence pulse generation
  switch:
    up:
      name: Write Mode
      description: Favors live/write behavior over loop playback
    middle:
      name: Loop Mode
      description: Starts in looping playback mode
    down:
      name: Tap/Shift Input
      description: Tap tempo and hold gestures for alternate parameter editing