pi-agent
f19e3f0633
- 01-basic-chord.py: chord progressions (C major) - 02-90s-dance-track.py: 5-track 90s dance (arp, bass, pads, drums, piano) - 03-arpeggiator.py: reusable arpeggio generator with dir/type options - 04-single-note.py: minimal single-note example - Rewrite compose_neon_dreams.py: cleaner track functions, proper velocity=0 note_off, tick helper - Add README.md with setup and API reference Uses MIDIUtil library (beats-based API) instead of mido (clocks-based API)
175 lines
5.9 KiB
Python
175 lines
5.9 KiB
Python
#!/usr/bin/env python3
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"""
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02-90s-dance-track.py - Full 90s dance track style composition
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Creates a multi-track 90s dance track with:
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- Track 1: Synthesizer arpeggio lead (GM patch 80)
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- Track 2: Synth bass (GM patch 37)
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- Track 3: Pad/choir (GM patch 88)
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- Track 4: Drums on channel 10
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- Track 5: Piano melody (GM patch 1)
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Uses MIDIUtil with time in beats (quarter notes).
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"""
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from midiutil import MIDIFile
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# ==============================
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# Constants / Configuration
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# ==============================
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BPM = 128
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TEMPO_US = int(60000000 / BPM)
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PPQ = 960 # Ticks per quarter note (MIDIUtil default)
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CHANNEL_DRUMS = 9 # MIDI channel 10 = channel index 9
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VOLUME = 100
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# === Chord data: (root, duration_beats, notes) ===
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# vi-IV-V-I in A minor: Am | F | G | E
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CHORD_PROGRESSION = [
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(57, 4), # Am: A3, C4, E4 - 4 beats
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(53, 4), # F: F3, A3, C4 - 4 beats
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(55, 4), # G: G3, B3, D4 - 4 beats
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(52, 4), # E: E3, G#3, B3 - 4 beats
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]
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# Arpeggio patterns: list of note offsets from chord root
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ARP_PATTERNS = [
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[0, 3, 7, 12], # Ascending: root-3rd-5th-octave
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[12, 7, 3, 0], # Descending: octave-5th-3rd-root
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]
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# ==============================
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# Create MIDI File
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# ==============================
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# Format 1: 5 user tracks + 1 tempo track = 6 total tracks
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midi = MIDIFile(5, file_format=1, ticks_per_quarternote=PPQ)
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midi.addTempo(0, 0, BPM) # Tempo goes to the implicit tempo track
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midi.addTrackName(0, 0, "Arpeggio Lead")
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midi.addTrackName(1, 0, "Synth Bass")
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midi.addTrackName(2, 0, "Warm Pad")
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midi.addTrackName(3, 0, "Drums (Ch10)")
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midi.addTrackName(4, 0, "Piano Melody")
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# ==============================
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# Track 0: Arpeggio Lead (GM Patch 80 - Lead 1 Synth)
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# ==============================
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track_arp = 0
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midi.addProgramChange(track_arp, 0, 0, 80)
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current_beat = 0
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for chord_root, chord_dur in CHORD_PROGRESSION:
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arp_idx = 0
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arp_pattern = ARP_PATTERNS[arp_idx % len(ARP_PATTERNS)]
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arp_idx += 1
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# Each chord tone gets a 1/4 note (1 beat / 4 arp notes = 1/4 beat per note)
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beat_duration = chord_dur / len(arp_pattern) # 1 beat / 4 = 0.25
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for i, (note_offset, next_offset) in enumerate(zip(arp_pattern, arp_pattern[1:] + arp_pattern[:0])):
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note = chord_root + note_offset
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if arp_idx % 2 == 0: # Descending on even patterns
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note = chord_root + arp_pattern[-1 - i]
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midi.addNote(track_arp, 0, note, current_beat + i * beat_duration, beat_duration, 90)
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current_beat += chord_dur
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arp_idx += 1
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# ==============================
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# Track 1: Synth Bass (GM Patch 37)
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# ==============================
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track_bass = 1
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midi.addProgramChange(track_bass, 0, 0, 37)
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current_beat = 0
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for chord_root, chord_dur in CHORD_PROGRESSION:
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# Root notes on beats 1 and 3 (quarter notes)
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midi.addNote(track_bass, 0, chord_root, current_beat, 0.5, 100)
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midi.addNote(track_bass, 0, chord_root + 7, current_beat + 2, 0.5, 95)
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current_beat += chord_dur
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# ==============================
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# Track 2: Warm Pad (GM Patch 88)
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# ==============================
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track_pad = 2
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midi.addProgramChange(track_pad, 0, 0, 88)
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# Add reverb and expression to pad
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midi.addControllerEvent(track_pad, 0, 0, 91, 60) # Reverb CC91 = 60
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midi.addControllerEvent(track_pad, 0, 0, 93, 70) # Chorus CC93 = 70
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current_beat = 0
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for chord_root, chord_dur in CHORD_PROGRESSION:
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# Pad plays the full chord for 3.5 of 4 beats with fade
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root = chord_root
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third = chord_root + 4
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fifth = chord_root + 7
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# Note On (pad instruments need note_on to sound)
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for pitch in [root, third, fifth]:
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midi.addNote(track_pad, 0, pitch, current_beat, chord_dur - 0.5, 70)
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current_beat += chord_dur
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# ==============================
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# Track 3: Drums (Channel 10 = MIDI channel 9)
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# Standard 90s dance pattern:
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# Kick on 1, 2, 3, 4 (kick = note 36)
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# Snare on 2, 4 (snare = note 38)
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# Closed HH on every eighth (hh closed = note 42)
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# Open HH on off-beats (hh open = note 46)
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# ==============================
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track_drums = 3
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current_beat = 0
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total_bars = len(CHORD_PROGRESSION) # One bar = 4 chords
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for bar in range(total_bars):
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for beat in range(4):
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# Kick on every quarter note
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midi.addNote(track_drums, CHANNEL_DRUMS, 36, current_beat + beat, 0.2, 110)
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# Snare on beats 2 and 4
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if beat in [1, 3]:
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midi.addNote(track_drums, CHANNEL_DRUMS, 38, current_beat + beat, 0.2, 100)
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# Closed hi-hat on every eighth note
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midi.addNote(track_drums, CHANNEL_DRUMS, 42, current_beat + beat + 0.5, 0.15, 80)
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# Open hi-hat on off-beats (between quarters)
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midi.addNote(track_drums, CHANNEL_DRUMS, 46, current_beat + beat + 0.25, 0.1, 70)
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midi.addNote(track_drums, CHANNEL_DRUMS, 46, current_beat + beat + 0.75, 0.1, 70)
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current_beat += 4 # One bar = 4 beats
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# ==============================
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# Track 4: Piano Melody (GM Patch 1)
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# Simple pentatonic melody in A minor
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# ==============================
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track_piano = 4
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midi.addProgramChange(track_piano, 0, 0, 1)
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# Melody notes: (beat, pitch, duration, velocity)
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melody_notes = [
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# Verse melody - A minor pentatonic
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(0, 69, 0.5, 95), # E4, half beat
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(0.5, 72, 0.5, 90), # F4
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(1.0, 69, 0.5, 85), # E4
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(1.5, 67, 0.5, 90), # D4
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(2.0, 65, 0.5, 95), # C4
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(2.5, 67, 0.5, 90), # D4
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(3.0, 69, 1.0, 85), # E4, whole beat
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# Repeat with variation
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(4.0, 69, 0.5, 95), # E4
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(4.5, 72, 0.5, 90), # F4
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(5.0, 74, 0.5, 95), # G4
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(5.5, 72, 0.5, 90), # F4
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(6.0, 69, 1.0, 85), # E4
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(7.0, 67, 0.5, 80), # D4
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(7.5, 65, 1.0, 75), # C4, whole beat
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]
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for beat, pitch, duration, vol in melody_notes:
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midi.addNote(track_piano, 0, pitch, beat, duration, vol)
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# ==============================
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# Write to Disk
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# ==============================
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with open("90s-dance-track.mid", "wb") as output_file:
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midi.writeFile(output_file)
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print("Written: 90s-dance-track.mid")
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print(f" Tracks: {len(CHORD_PROGRESSION)} chord bars at {BPM} BPM")
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