MidiGen is a Python library designed to make creating and manipulating MIDI files as simple and intuitive as possible. Whether you're a developer looking to integrate music generation into your application, a musician experimenting with algorithmic composition, or a hobbyist exploring the world of MIDI, MidiGen provides the tools you need to bring your musical ideas to life.
Built on top of the robust mido library, MidiGen offers a high-level, object-oriented API that abstracts away the complexities of the MIDI protocol. From crafting simple melodies to orchestrating multi-track songs with complex chord progressions, MidiGen streamlines the entire process.
- High-Level Song Structure: Organize your music into
SongandSectionobjects, making it easy to compose with familiar concepts like verses and choruses. - Music Theory-Powered Composition: Generate
ChordProgressions from Roman numeral notation (e.g., "I-IV-V-I"). MidiGen leverages themusic21library to handle the music theory for you. - Multi-Track Support: Create rich, layered compositions by adding multiple tracks to your
MidiGenobject. - Named Instruments: Assign instruments to your tracks using a comprehensive list of General MIDI instrument names. No need to memorize MIDI program numbers!
- Drum Kits: Easily create rhythm tracks using the
DrumKitclass and a dictionary of standard drum names. - Advanced Musical Constructs: Effortlessly add notes, chords, and arpeggios with various patterns (ascending, descending, alternating).
- Full MIDI Control: Fine-tune your compositions with control over tempo, time signature, key signature, and more.
First, ensure you have Python 3.7+ installed. Then, you can install MidiGen using pip:
pip install midigen-libAlternatively, for development, clone the repository and install with Poetry:
git clone https://github.com/cainky/midigen.git
cd midigen
poetry installThe easiest way to get started with MidiGen is by using the Song class. Here's how you can create a simple song with a classic I-V-vi-IV chord progression:
from midigen import Song, Section, Key
# 1. Create a Song with a key and tempo
song = Song(key=Key("C", "major"), tempo=120)
# 2. Add a section with a chord progression
song.add_section(Section(name="Verse", length=8, chord_progression="I-V-vi-IV"))
# 3. Add an instrument to play the progression
song.add_instrument("Acoustic Grand Piano")
# 4. Generate the notes for the instrument
song.generate(instrument_name="Acoustic Grand Piano")
# 5. Save the MIDI file
song.save("my_first_song.mid")
print("Song 'my_first_song.mid' created successfully!")MidiGen makes it easy to create multi-track songs. Simply add as many instruments as you like, and MidiGen will automatically assign them to new tracks.
from midigen import Song, Section, Key
# Create a song
song = Song(key=Key("Am", "minor"), tempo=90)
# Define the song structure
song.add_section(Section(name="Intro", length=4, chord_progression="i-VI-III-VII"))
song.add_section(Section(name="Verse", length=8, chord_progression="i-VI-III-VII-i-VI-iv-V"))
# Add instruments, which will be assigned to separate tracks
song.add_instrument("Synth Bass 1")
song.add_instrument("String Ensemble 1")
song.add_instrument("Lead 1 (square)")
# Generate the parts for each instrument
song.generate(instrument_name="Synth Bass 1", octave=3)
song.generate(instrument_name="String Ensemble 1", octave=4)
song.generate(instrument_name="Lead 1 (square)", octave=5)
# Save the multi-track MIDI file
song.save("multi_track_song.mid")You can add a rhythm section to your song using the DrumKit class.
from midigen import MidiGen, DrumKit, Key
# Use the lower-level MidiGen for more control
midi = MidiGen(key=Key("C"))
# Create a drum kit
drum_kit = DrumKit()
# Add drum sounds at specific times (in ticks)
# A simple 4/4 rock beat
for i in range(4):
beat_start_time = i * 480
drum_kit.add_drum("Bass Drum 1", time=beat_start_time)
drum_kit.add_drum("Acoustic Snare", time=beat_start_time + 240)
drum_kit.add_drum("Closed Hi Hat", time=beat_start_time)
drum_kit.add_drum("Closed Hi Hat", time=beat_start_time + 120)
drum_kit.add_drum("Closed Hi Hat", time=beat_start_time + 240)
drum_kit.add_drum("Closed Hi Hat", time=beat_start_time + 360)
# Add the drum kit to a track
# Note: Drum tracks are typically on channel 9
track = midi.get_active_track()
track.add_drum_kit(drum_kit)
midi.save("drum_beat.mid")Use the Arpeggio class to add flowing arpeggios to your tracks.
from midigen import MidiGen, Note, Arpeggio, ArpeggioPattern, Key, KEY_MAP
midi = MidiGen(tempo=140, key=Key("C"))
track = midi.get_active_track()
# Define the notes of a C major 7 chord
c_maj7_notes = [
Note(pitch=KEY_MAP["C4"], velocity=70, duration=120, time=0),
Note(pitch=KEY_MAP["E4"], velocity=70, duration=120, time=0),
Note(pitch=KEY_MAP["G4"], velocity=70, duration=120, time=0),
Note(pitch=KEY_MAP["B4"], velocity=70, duration=120, time=0)
]
# Create an ascending arpeggio
arpeggio = Arpeggio(
notes=c_maj7_notes,
pattern=ArpeggioPattern.ASCENDING,
delay=120, # Delay between notes in ticks
loops=4
)
track.add_arpeggio(arpeggio)
midi.save("arpeggio_example.mid")For maximum control, you can bypass the Song composer and interact directly with MidiGen, Track, Note, and Chord objects.
from midigen import MidiGen, Track, Note, Chord, Key, KEY_MAP
# Create a MidiGen instance
midi_gen = MidiGen(tempo=120, time_signature=(4, 4), key_signature=Key("C"))
# Get the default track
track = midi_gen.get_active_track()
# Add individual notes
note_c = Note(pitch=KEY_MAP["C4"], velocity=64, duration=480, time=0)
track.add_note(note_c)
# Add a chord
note_e = Note(pitch=KEY_MAP["E4"], velocity=64, duration=480, time=480)
note_g = Note(pitch=KEY_MAP["G4"], velocity=64, duration=480, time=480)
c_major_chord = Chord([note_e, note_g])
track.add_chord(c_major_chord)
midi_gen.save("low_level_example.mid")Contributions are welcome! Please see CONTRIBUTING.md for details on how to get started.
MidiGen is distributed under the GNU General Public License, Version 3. Please see the LICENSE file for more information.