🎹 Akkordgen – Generate MIDI files from chord progressions

Akkordgen is a CLI tool for converting readable chord progressions into playable MIDI files. It supports rich chord types, Unicode and ASCII accidentals, and variable beat durations.

It pairs perfectly with ChordGPT, a ChatGPT-powered assistant that helps you compose progressions in the correct format.

🚀 Installation

Requries that you have installed node/npm.

npm install -g akkordgen

You can now run akkordgen from anywhere in your terminal.

🧠 Format

Chord progressions must follow this grammar:

• Chords use the format: <root><type>:<duration>
• Bars are separated by |, and the progression must end with ||
• Both Unicode and ASCII accidentals are supported:
  • ♯ or # for sharp
  • ♭ or b for flat
• Duration is in beats (e.g. 0.25, 0.5, 1, 2, 4)

Examples:

F♯m7:4 | B7:4 | Emaj7:4 ||
Cmaj7:2 Dm7:2 | G7:4 ||
A#m7:1 G#7:1 D#m7:2 | F#maj7:4 ||

🧪 Usage

Basic usage:

akkordgen "F#m7:4 | B7:4 | Emaj7:4 ||" progression.mid

This generates a file called progression.mid.

🤖 Compose with ChordGPT

ChordGPT is a ChatGPT-based assistant designed to help you:

• Compose harmonically sound progressions
• Explore keys, moods, and rhythmic structures
• Output progressions directly in Akkordgen format

Example prompt:

Give me a jazzy ii–V–I in G major with 2 beats per chord.

ChordGPT output:

Am7:2 D7:2 | Gmaj7:4 ||

You can paste this directly into akkordgen.

🧑‍💻 License

MIT © Lars-Erik Bruce