#!/usr/bin/env python3
"""
Example: Generate a simple MIDI file.
This demonstrates the MIDI export pipeline - the endpoint of the system.
Run this script to create a playable MIDI file you can open in any DAW.
Usage:
python examples/generate_midi.py
# Creates: examples/output/four_on_floor.mid
"""
from pathlib import Path
from chuk_mcp_music.compiler.midi import (
DRUM_CHANNEL,
TICKS_PER_BEAT,
MidiEvent,
create_test_midi,
events_to_midi,
)
def main() -> None:
"""Generate example MIDI files."""
output_dir = Path(__file__).parent / "output"
output_dir.mkdir(exist_ok=True)
# Example 1: Simple four-on-floor drum pattern (4 bars)
print("Generating four_on_floor.mid...")
mid = create_test_midi(tempo_bpm=124)
mid.save(str(output_dir / "four_on_floor.mid"))
print(f" Created: {output_dir / 'four_on_floor.mid'}")
# Example 2: Custom pattern - simple bassline
print("\nGenerating simple_bassline.mid...")
bassline = create_simple_bassline()
bassline.save(str(output_dir / "simple_bassline.mid"))
print(f" Created: {output_dir / 'simple_bassline.mid'}")
# Example 3: Combined drums + bass
print("\nGenerating drums_and_bass.mid...")
combined = create_drums_and_bass()
combined.save(str(output_dir / "drums_and_bass.mid"))
print(f" Created: {output_dir / 'drums_and_bass.mid'}")
print("\nDone! Open the MIDI files in your DAW to hear them.")
def create_simple_bassline():
"""
Create a simple bassline following a i-VI-III-VII progression in D minor.
This demonstrates:
- Creating MidiEvents manually
- Using different pitches for chord roots
- Setting velocity for dynamics
"""
events: list[MidiEvent] = []
ticks_per_bar = TICKS_PER_BEAT * 4 # 4/4 time
# D minor progression: Dm - Bb - F - C
# MIDI notes: D2=38, Bb1=34, F2=41, C2=36
progression = [38, 34, 41, 36] # Root notes for i, VI, III, VII
# 4 bars, one chord per bar
for bar, root_note in enumerate(progression):
bar_start = bar * ticks_per_bar
# Quarter note pulse on the root
for beat in range(4):
events.append(
MidiEvent(
pitch=root_note,
start_ticks=bar_start + beat * TICKS_PER_BEAT,
duration_ticks=TICKS_PER_BEAT - 20, # Slightly shorter for separation
velocity=100 if beat == 0 else 80, # Accent on downbeat
channel=0, # Bass channel
)
)
return events_to_midi(events, tempo_bpm=124)
def create_drums_and_bass():
"""
Create a combined drums and bass pattern.
This demonstrates:
- Multiple channels (drums on 9, bass on 0)
- Layered patterns
- 8 bars of music
"""
events: list[MidiEvent] = []
ticks_per_bar = TICKS_PER_BEAT * 4
# D minor progression repeated twice: Dm - Bb - F - C - Dm - Bb - F - C
progression = [38, 34, 41, 36, 38, 34, 41, 36]
for bar in range(8):
bar_start = bar * ticks_per_bar
root_note = progression[bar]
# DRUMS (channel 9)
# Kick on 1 and 3
for beat in [0, 2]:
events.append(
MidiEvent(
pitch=36, # Kick
start_ticks=bar_start + beat * TICKS_PER_BEAT,
duration_ticks=TICKS_PER_BEAT // 2,
velocity=100,
channel=DRUM_CHANNEL,
)
)
# Snare on 2 and 4
for beat in [1, 3]:
events.append(
MidiEvent(
pitch=38, # Snare
start_ticks=bar_start + beat * TICKS_PER_BEAT,
duration_ticks=TICKS_PER_BEAT // 2,
velocity=90,
channel=DRUM_CHANNEL,
)
)
# Hi-hat on every eighth
for eighth in range(8):
events.append(
MidiEvent(
pitch=42, # Closed hi-hat
start_ticks=bar_start + eighth * (TICKS_PER_BEAT // 2),
duration_ticks=TICKS_PER_BEAT // 4,
velocity=60 if eighth % 2 == 0 else 40,
channel=DRUM_CHANNEL,
)
)
# BASS (channel 0)
# Eighth note pulse
for eighth in range(8):
events.append(
MidiEvent(
pitch=root_note,
start_ticks=bar_start + eighth * (TICKS_PER_BEAT // 2),
duration_ticks=(TICKS_PER_BEAT // 2) - 10,
velocity=90 if eighth % 2 == 0 else 70,
channel=0,
)
)
return events_to_midi(events, tempo_bpm=124)
if __name__ == "__main__":
main()
