Raven:
Harmony Engine
★★★★★
(84)
Harmony Engine & Audio/MIDI Analyser / Chord, Melody & Bass Generator
Overview
Raven: Harmony Engine is a professional-grade VST3 MIDI harmony and analysis plugin built for producers, composers, and sound designers who want a deeper understanding of the music they create.
Combining real-time MIDI and audio analysis with a fully featured chord library, chord generator, bass generator, and melody generator — all driven by 25 genre-specific style presets — Raven gives you everything you need to make informed harmonic decisions, explore new ideas, and export MIDI directly from your DAW, all in one focused, dark-themed interface.
39
Scales
25
Genre Styles
492
Chord Library Entries
41
Chord Types
VST3
Windows 64-bit
MIDI Analysis
Key Detection
Raven analyses the note content of your MIDI and reports the most likely root key and scale. The detected key, confidence level, total note count, and track count are all displayed at a glance in the Key Detection panel. BPM is read directly from the file's tempo event and can be overridden with the BPM slider.
Root Key & Scale / Mode Selection
Override or confirm the detected key by selecting any of the 12 chromatic root keys directly from the interface. Pair it with your choice of scale or mode — 39 scales across diatonic, modal, jazz, world, and experimental categories. The Notes in Key keyboard highlights in-key and out-of-key notes instantly.
MIDI Overview (Piano Roll)
A full piano roll visualisation of the loaded MIDI file renders across all tracks and voices. See the rhythmic and melodic shape of your content at a glance without leaving your DAW.
Note Frequency
A bar chart breakdown of how often each pitch class appears in the loaded file. Immediately reveals the tonal centre and any dominant or avoided notes in the performance.
Drop any MIDI file or Ableton clip into Raven and instantly get a full harmonic breakdown of its contents.
Audio Analysis
Drop any audio file into Raven to get a live spectrogram and real-time key detection from the audio signal.
Spectrogram
A scrolling time-frequency spectrogram built on a 4096-point FFT with 87.5% overlap renders the full spectral history of the loaded audio. Spot sustained frequencies, transient events, and spectral gaps across the entire timeline.
Spectrum View
Toggle to a standard frequency spectrum display for a snapshot view of the current spectral balance. Switch between Spectrogram and Spectrum modes with a single click — no menus required.
Key Detection Integration
Chroma data extracted from the spectrogram feeds directly into the same key detection pipeline used for MIDI analysis — a consistent harmonic read from audio or MIDI.
Diatonic Harmony
Load a MIDI file and Raven maps every chord and note event to your selected key and scale, producing a full diatonic harmony grid. Each chord block is labelled with its Roman numeral function, making it straightforward to see progressions, identify borrowed chords, and understand the harmonic movement of any piece.
Drag to Export
Click and drag any chord block directly out of the harmony grid into your DAW. Drag a single chord or a full progression — Raven generates the MIDI clip on the fly, ready to drop onto any instrument track.
Chord Library
The Chord Library is a searchable, filterable reference of every chord type available in Raven — 41 chord types voiced across all 12 root keys, giving you 492 unique chords to browse, preview, and drag directly into your project.
| Category | Chord Types |
|---|---|
| Triads | Major, Minor, Diminished, Augmented, Sus2, Sus4, Power, Flat 5 |
| 6th Chords | Major 6, Minor 6, 6/9 |
| 7th Chords | Major 7, Minor 7, Dominant 7, Diminished 7, Half-Dim 7, Minor-Maj 7, Augmented 7, Augmented Maj7, Dom 7 Sus4 |
| 9th Chords | Major 9, Minor 9, Dominant 9, Add 9, Minor Add9, Flat 9 (7b9), Sharp 9 (7#9) |
| 11th Chords | Major 11, Minor 11, Dominant 11, Sharp 11 (7#11), 9 Sus4 |
| 13th Chords | Major 13, Minor 13, Dominant 13 |
| Extended & Altered | Dom 7b5, Dom 7#5, Maj7#11, Min-Maj9, Quartal, Quintal |
Scale Filter
Narrow the library to only the chords that fit a specific scale and root key — Raven hides any chord containing a note outside your chosen scale.
Search
Type any chord name, quality, or symbol (e.g. "maj7", "sus", "dim") to instantly filter the library to matching results.
Preview
Click any chord card to trigger an instant audio preview through Raven's built-in synth before committing.
Drag to Export
Every chord card can be dragged directly into your DAW as a named MIDI clip, ready to drop onto any instrument track.
Alternate Note Suggestions
Pink notes are out of scale — Raven identifies these and offers ranked substitutions in the Alternate Note Suggestions panel.
When a note falls outside the detected key, Raven's Alternate Note Suggestions panel offers context-aware substitutions.
Context-Aware Ranking
Each suggestion is ranked by how well it fits the current scale and harmonic context, giving you practical options to resolve tension, stay diatonic, or make an informed decision to keep the original note for colour.
Generator
Switch to the Generate tab to build chord progressions, bass lines, and lead melodies from scratch — no MIDI file required. Four modes are accessible from tabs at the top of the panel: Chords, Lead Melody, Bass, and Chord Library.
Root Key & Scale
Sets the harmonic context for all generated content. All 39 scales available across all 12 root keys — shared across the Chord, Lead, and Bass generators simultaneously.
No File Required
Generate progressions, melodies, and bass lines independently — the Generator operates without any loaded MIDI or audio file.
Style Presets
A dedicated Style selector biases all three generators toward the harmonic, rhythmic, and voicing conventions of 25 genre presets — from Neo Soul and Jazz/Fusion to Dark Trap, Melodic Techno, Bossa Nova, and Flamenco. Also available as a filter in the MIDI Analyze tab.
Tempo
A shared BPM slider controls the playback tempo and MIDI timing of all generated content across all three generators. Range: 40–250 BPM.
Chord Generator
Generates harmonically voiced chord progressions drawn from common-practice voice-leading and weighted progression logic.
| Parameter | Description |
|---|---|
| Bars | Set the length of the generated progression from 1 to 16 bars |
| Rhythm Var | Controls rhythmic variation from static whole-bar chords to subdivided, syncopated patterns |
| Inversions | Sets the maximum inversion depth (0–3) applied during voice leading |
| Voicing Spread | Controls the vertical spread of each chord from tight close position to wide open voicing |
| Velocity Var | Introduces humanised velocity variation across chord notes |
| Musicality | Biases the generator between fully random harmonic choices and strongly weighted common-practice progressions — at maximum, the engine heavily favours proven classical and contemporary chord movements |
Lead Melody Generator
Generates scale-locked single-note melodies with phrase-aware rhythm and voice-led motion.
| Parameter | Description |
|---|---|
| Bars | Set the length of the generated progression from 1 to 16 bars |
| Density | Controls note density from sparse, long-note phrases to busy sixteenth-note lines |
| Leapiness | Shifts the balance between smooth stepwise motion and larger melodic leaps |
| Rhythm Var | Introduces rhythmic variation and irregular note lengths within the phrase |
| Velocity Var | Humanises the velocity of each note, with phrase-end softening at high Musicality |
| Octave Range | Spans the melody across 1 to 3 octaves depending on the setting |
| Musicality | At higher values, biases toward stepwise motion, stronger tonic resolution at phrase ends, and scale degrees that sit most naturally in the key (root, 3rd, 5th) |
Tempo
A shared BPM slider controls the tempo of all generated content. Range: 40–250 BPM.
Preview
Each generated pattern has a dedicated play button and a mini piano roll display. Audition the result through the built-in synth before exporting.
Drag to Export
The Chord, Lead Melody, and Bass rolls can all be dragged directly into your DAW as a named MIDI clip for easy session organisation.
Bass Generator
Generates rhythmically driven, harmonically grounded bass lines locked to the current key and scale. The Bass Generator uses root-motion logic and groove quantisation to produce lines that sit naturally under chord progressions — from steady whole-note roots to syncopated walking patterns.
| Parameter | Description |
|---|---|
| Bars | Set the length of the generated bass line from 1 to 16 bars |
| Groove | Controls the rhythmic feel from straight quantised notes to swung, syncopated patterns — higher values push notes off the grid for a more human feel |
| Note Length | Sets the average sustain of each bass note from short, staccato hits to long, legato tones — shapes the envelope and energy of the line |
| Velocity Var | Introduces humanised velocity variation across the bass line, preventing mechanical uniformity between notes |
| Movement | Controls how much the bass line moves harmonically — low values keep the line anchored to the root, while high values introduce passing tones, scale runs, and chromatic approach notes |
Drag to Export
The Bass roll can be dragged directly out of Raven into your DAW as a named MIDI clip, ready to drop onto any bass instrument or sampler track.
Style Presets
Raven includes 25 genre-specific Style presets that bias the Chord, Lead, and Bass generators toward the harmonic language, voicing conventions, and rhythmic tendencies of each style. Selecting a style shapes the types of chords generated, the extensions used, the rhythmic feel, and the melodic density — without ever overriding your chosen key or scale. The same Style selector is also available in the MIDI Analyze tab to filter the Diatonic Harmony grid to style-appropriate chord types.
| Style | Character |
|---|---|
| Default | Standard diatonic generation — no style bias applied |
| Neo Soul | Rich extended chords — 9ths, 11ths, quartal voicings, lush ii-V-I progressions |
| Lo-Fi Hip Hop | Jazzy maj7/min9 chords, slow harmonic rhythm, chill ii-V-I loops |
| Jazz / Fusion | Altered dominants, rootless voicings, quartal harmony, dense extensions |
| Gospel | Passing dim7 chords, rich maj9 tonic and subdominant, dramatic tension-release |
| Soul / Funk | Tight rhythmic chords — 6ths, 9ths, dominant 7ths, syncopated stabs |
| Modern R&B | Polished pop-soul extended chords — 7ths, 9ths with cleaner voicings |
| Dark Trap | Minor 7ths, half-diminished, sparse atmospheric chords — 808-friendly |
| Bossa Nova | Smooth maj7/min9 chords, gentle syncopation, II-V-I in major |
| Melodic Techno | Sparse minor pads, slow hypnotic changes, harmonic minor colour — Afterlife / ARTBAT style |
| Deep House | Warm maj7/min7 jazz chords, soulful ii-V-I loops — Rhodes / Larry Heard style |
| Progressive House | Uplifting I-V-vi-IV anthems, open maj7/add9 voicings — Deadmau5 / Eric Prydz style |
| Tech House | Minimal chord stabs, dominant 7th vamps, groove-forward — Fisher / John Summit style |
| Future Bass | Stacked maj7/add9 pads across octaves, lush emotional builds — Flume / ODESZA style |
| Trance | Epic minor sus chords, long pads, anthemic 8-bar progressions — Tiësto / A&B style |
| Ambient | Static sus2/sus4 and modal clusters, no resolution, very slow changes — Eno / Burial style |
| Drum & Bass | Half-time minor jazz pads over breakbeats, m7/maj7 — LTJ Bukem / Hospital style |
| Afro House | Pentatonic 6/9 chords, Dorian modal colour, rhythmic displaced stabs — Black Coffee style |
| Hyperpop | Dissonant augmented/add9 clusters, chromatic instability, chaotic rhythm — SOPHIE / A.G. Cook style |
| Brostep | Dark harmonic minor, power chords, 7#9/7b9 wobble tension — Skrillex / Excision style |
| Melodic Dubstep | Emotional minor pads, i-VI-III-VII, lush m9/maj7 — Illenium / Seven Lions style |
| Salsa / Son | Montuno vamps, I-VI7-II7-V7 backcycling, 6/9 chords, syncopated stabs — Tito Puente / Celia Cruz style |
| Flamenco | Andalusian cadence i-bVII-bVI-V, 7b9 tension, dim7 passing chords — Paco de Lucía style |
| Samba | Chromatic ii-V-I, 6/9 tonic, maj7#11 Lydian colour, aug7 passing — Jobim / João Gilberto style |
| Reggaeton | Minor dembow stabs, m7/m9 sparse chords, dark vi-IV-I-V — Bad Bunny / J Balvin style |
Scale Reference
Raven includes 39 scales available across the MIDI Analysis key selector, Chord Library filter, and Generator — covering everything from standard Western modes to jazz, bebop, world, and experimental scales:
| Category | Scales | Count |
|---|---|---|
| Diatonic & Modal | Major, Natural Minor, Dorian, Phrygian, Lydian, Mixolydian, Locrian | 7 |
| Harmonic & Melodic | Harmonic Minor, Melodic Minor, Harmonic Major | 3 |
| Pentatonic & Blues | Pentatonic Major, Pentatonic Minor, Blues | 3 |
| Symmetric | Whole Tone, Diminished, Half-Whole Diminished, Whole-Half Diminished | 4 |
| Jazz & Bebop | Lydian Dominant, Phrygian Dominant, Super Locrian, Lydian Augmented, Dorian b2, Bebop Major, Bebop Dorian, Bebop Dominant | 8 |
| World & Classical | Hungarian Minor, Double Harmonic, Persian, Neapolitan Major, Neapolitan Minor, Spanish Phrygian | 6 |
| Japanese | Hirajoshi, Iwato, In Scale, Insen, Yo Scale | 5 |
| Experimental | Enigmatic, Prometheus, Tritone | 3 |
Workflow
01Loads in Analyse / MIDI view by default — drop a file and get results immediately
02Switch between MIDI and Audio analysis with one click
03Select a Style preset in the Analyze tab to filter the Diatonic Harmony grid to style-appropriate chord types
04Switch to Generate tab to build chord progressions, bass lines, and melodies independently of any loaded file
05Set a Style preset in the Generator to shape the harmonic language, voicing, and groove of all three generators at once
06Chord Library, Chord Generator, Lead Melody Generator, and Bass Generator all share the same root key and scale context
07Scale filter in the Chord Library updates live as you change root and scale selection
08Drag-to-export MIDI works from the Diatonic Harmony grid, Chord Library, Chord Generator, Lead Melody Generator, and Bass Generator
09Key, scale, style, root selection, and BPM are all accessible without any menu diving
10Resizable window to suit any screen layout
Technical Specifications
| Feature | Specification |
|---|---|
| MIDI Analysis | |
| Supported format | Standard MIDI File (.mid), Ableton clip drag & drop |
| Key detection | Chroma-based pitch class analysis with confidence scoring |
| Tempo detection | File tempo event read + manual BPM override (40–250 BPM) |
| Piano roll | Per-track, all voices, full file length |
| Note frequency analysis | 12 pitch class breakdown |
| Audio Analysis | |
| FFT size | 4096 points |
| FFT window | Hann window |
| Overlap | 87.5% (hop size = FFT ÷ 8) |
| Chroma extraction | 12-bin pitch class from magnitude spectrum |
| Chord Library | |
| Chord types | 41 |
| Root keys | 12 |
| Total unique chords | 492 |
| Scale compatibility filter | All 39 scales |
| Generator | |
| Generator tabs | 4 (Chords, Lead Melody, Bass, Chord Library) |
| Chord generator controls | 6 (Bars, Rhythm Var, Inversions, Voicing Spread, Velocity Var, Musicality) |
| Lead melody controls | 7 (Bars, Density, Leapiness, Rhythm Var, Velocity Var, Octave Range, Musicality) |
| Bass generator controls | 5 (Bars, Groove, Note Length, Velocity Var, Movement) |
| Style presets | 25 (available in Generator and MIDI Analyze tab) |
| Tempo range | 40–250 BPM |
| General | |
| Scale library | 39 scales |
| Style presets | 25 genre styles |
| Format | VST3 |
| Platform | Windows (64-bit) |
System Requirements
DAW
Any VST3-compatible DAW — Ableton Live 11+, FL Studio 20+, Bitwig, Reaper, Cubase, Studio One, and others.
OS
Windows 10 or 11 (64-bit). Mac support coming in a future release.
Format
VST3 only. No iLok, no internet connection required after activation.
Version
Current release: 1.0. Free updates for all future 1.x releases.
License Info
Personal & Commercial Use
Use in any personal or commercial project — music production, mixing, mastering, post-production, broadcast, and live performance.
Single User
One license per user. Install on up to 3 machines you personally own or operate.
Free Updates
All 1.x updates are free. Your serial activates the current version and all future updates in the 1.x release line.
No Redistribution
The plugin binary may not be shared, resold, or redistributed. Each user must obtain their own license.
Free