Bonfire Chords

In Development

Polyphonic chord synthesizer with intelligent voicing, triple oscillators, and inter-plugin sync.

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Bonfire Chords screenshot 1

Overview

Bonfire Chords is a VST3/AU polyphonic synthesizer that generates full chords from single MIDI notes with intelligent harmonic expansion. It combines a chord engine (AutoChord, ChordMemory), triple oscillator bank with wavetable/FM synthesis, chord sequencer, arpeggiator, strum engine, and a modular FX chain — all connected via the Bonfire Sync protocol for real-time state sharing between plugin instances.

Tech Stack

Language: C++20 (no extensions)Framework: JUCE (latest, FetchContent)Build: CMake 3.22+Shared Library: BonfireDSP — reusable DSP library with 6 filter models, 6 effects, MSEG, LFO, wavetable loader, and music theory types. Designed for reuse across the Bonfire Audio plugin family.UI: React 18 + TypeScript + Vite, embedded via JUCE WebBrowserComponentState: Zustand store synced bidirectionally with JUCE APVTSTesting: Catch2 v3.5.3 — ~1,934 lines of test code across 5 test suitesPlugin Formats: AU, VST3, Standalone

Engineering Highlights

  1. 01Shared BonfireDSP library — Extracted reusable C++20 static library with 6 filter implementations (SVF, Ladder, Diode, SEM, Comb, Formant), 6 effects (Dattorro reverb, chorus, delay, phaser, distortion, parametric EQ), MSEG, LFO, wavetable loader, and music theory types. Designed for reuse across all Bonfire Audio plugins.
  2. 02Bonfire Sync protocol — Inter-plugin communication via shared memory. Leader broadcasts harmonic state (scale, root, chord) to followers in real-time. Enables Bonfire Bass and Bonfire Chords to stay harmonically synced in a DAW session.
  3. 0332-voice polyphony with intelligent voicing — Chord expansion from single MIDI notes with diatonic awareness, inversions, and drop voicings. Voice stealing balances oldest and quietest notes.
  4. 04Dual filter architecture — 6 filter models from BonfireDSP with flexible routing (series/parallel/dual-mono). Each filter has cutoff, resonance, drive, key tracking, velocity tracking, and envelope modulation.
  5. 05React WebView UI with bidirectional bridge — Same architecture as Bonfire Bass. Zustand state synced with JUCE APVTS via JSON messaging, audio-thread-safe.
  6. 06Modular FX rack — 8-slot drag-reorderable effects chain using BonfireDSP effect factory pattern. Each slot can host any effect type.

Stats

~16,000 LOC C++ (excluding tests and presets)
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~1,934 lines of test code across 5 suites (synth, effects, sequencer, chord engine, mod matrix)
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12,263 lines of factory preset data
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23 commits (rapid 2-day development sprint, March 2026)
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32-voice polyphony, triple oscillators, 6 filter models, 6 effects
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