Music Composer

Comprehensive music composition assistant with expertise in theory, MIDI programming, synthesis, and all musical genres from classical to electronic.

Core Capabilities

1. Music Composition & Arrangement

• Generate melodies, harmonies, bass lines, and rhythmic patterns
• Create full arrangements with multiple instruments
• Orchestrate for various ensembles (orchestra, band, electronic, etc.)
• Develop chord progressions and harmonic structures
• Write counterpoint and polyphonic textures

2. MIDI Programming

• Create MIDI files programmatically using Python (mido library)
• Generate drum patterns, arpeggios, and sequences
• Implement realistic velocity curves and humanization
• Use scripts in scripts/ for common MIDI tasks
• Export production-ready MIDI files

3. Genre Expertise

All genres supported - consult references/genres.md for specific characteristics:

• Classical (Baroque, Romantic, Contemporary)
• Jazz (Bebop, Modal, Fusion, Smooth)
• Electronic (Techno, House, Ambient, IDM, Dubstep)
• Rock & Metal (Progressive, Blues, Punk)
• Pop & R&B (Contemporary, Soul)
• World Music (Latin, African, Asian traditions)
• Film/Game Scoring

4. Music Theory & Analysis

Comprehensive theory support - see references/theory.md:

• Scales (Major, Minor, Modal, Exotic)
• Chord construction and voicings
• Harmonic progressions and functions
• Form and structure analysis
• Rhythmic concepts and time signatures

5. Audio Synthesis Guidance

Provide synthesis programming advice for:

• Subtractive synthesis (oscillators, filters, envelopes)
• FM synthesis (operators, algorithms)
• Wavetable and granular synthesis
• Effects chains and processing

Quick Start Workflows

Compose a Melody

# Use the melody generator script
python scripts/generate_melody.py --key C --scale major --length 16 --output melody.mid

Create a Chord Progression

# Generate progression with voice leading
python scripts/generate_chords.py --progression "I-IV-V-I" --key G --output chords.mid

Build a Drum Pattern

# Create rhythmic pattern
python scripts/generate_drums.py --style "rock" --tempo 120 --bars 4 --output drums.mid

Full Arrangement

Combine elements into complete composition:

1. Define structure (intro, verse, chorus, etc.)
2. Create chord progression for each section
3. Generate melody over chords
4. Add bass line following harmony
5. Program drums and percussion
6. Add additional instruments/textures
7. Export multi-track MIDI

Working with Musical Requests

"Compose a jazz ballad in Bb"

1. Choose jazz ballad chord progression (consult references/progressions.md)
2. Set tempo (60-80 BPM typically)
3. Create walking bass line
4. Add jazz piano voicings
5. Compose melody with jazz phrasing
6. Add subtle drums (brush pattern)
7. Export MIDI with proper track names

"Create a techno track with a driving bassline"

1. Set tempo (125-135 BPM)
2. Create 4-on-the-floor kick pattern
3. Generate repetitive bassline (often single note or octaves)
4. Add hi-hats and percussion
5. Create synth leads/stabs
6. Layer atmospheric pads
7. Structure: Intro → Build → Drop → Break → Drop → Outro

"Write a string quartet movement"

1. Choose form (Sonata, Rondo, Theme & Variations)
2. Compose main themes
3. Distribute among instruments (Violin I, Violin II, Viola, Cello)
4. Develop counterpoint and voice leading
5. Consider range and playability
6. Export with separate tracks for each instrument

MIDI Technical Details

General MIDI (GM) Program Numbers

Consult references/gm_instruments.md for complete list:

• 0: Acoustic Grand Piano
• 24: Acoustic Guitar (nylon)
• 32: Acoustic Bass
• 40: Violin
• 128+: Drum kits (channel 10)

MIDI Note Numbers

Middle C = 60 (C4) Range: 0-127 (C-1 to G9)

Velocity Guidelines

• ppp: 8-20
• pp: 21-35
• p: 36-50
• mp: 51-65
• mf: 66-80
• f: 81-95
• ff: 96-110
• fff: 111-127

Humanization Techniques

• Slight velocity variation (±5-10)
• Micro-timing adjustments (±10-30 ticks)
• Avoid perfectly quantized notes
• Vary note lengths slightly

Music Theory Quick Reference

Common Chord Progressions

• Pop: I-V-vi-IV (C-G-Am-F)
• Blues: I-I-I-I-IV-IV-I-I-V-IV-I-I
• Jazz: ii-V-I (Dm7-G7-Cmaj7)
• Rock: I-bVII-IV (C-Bb-F)

See references/progressions.md for comprehensive list.

Scale Formulas

• Major: W-W-H-W-W-W-H
• Natural Minor: W-H-W-W-H-W-W
• Harmonic Minor: W-H-W-W-H-W+H-H
• Pentatonic Major: W-W-m3-W-m3

See references/scales.md for all modes and exotic scales.

Best Practices

Composition

• Start with a clear concept or emotion
• Consider the target context (film, game, standalone)
• Use repetition with variation
• Balance complexity and accessibility
• Think in terms of call-and-response

MIDI Production

• Use appropriate velocity ranges for realism
• Pan instruments for spatial clarity
• Layer sounds for richness
• Leave headroom for mixing
• Include tempo and time signature changes when needed

Arrangement

• Don't overcrowd the frequency spectrum
• Create contrast between sections
• Use dynamics effectively
• Consider the listener's attention span
• Build and release tension

Resources Overview

Scripts (scripts/)

• generate_melody.py - Melodic line generator
• generate_chords.py - Chord progression creator
• generate_drums.py - Rhythm pattern generator
• midi_utils.py - Shared MIDI utilities

References (references/)

• theory.md - Complete music theory reference
• genres.md - Genre characteristics and conventions
• scales.md - All scale types and formulas
• progressions.md - Common chord progressions by genre
• gm_instruments.md - General MIDI instrument list
• orchestration.md - Instrument ranges and combinations

Assets (assets/)

• templates/ - MIDI templates for common setups
• drum_patterns/ - Pre-made drum MIDI files

Resources

This skill includes example resource directories that demonstrate how to organize different types of bundled resources:

scripts/

Executable code (Python/Bash/etc.) that can be run directly to perform specific operations.

Examples from other skills:

• PDF skill: fill_fillable_fields.py, extract_form_field_info.py - utilities for PDF manipulation
• DOCX skill: document.py, utilities.py - Python modules for document processing

Appropriate for: Python scripts, shell scripts, or any executable code that performs automation, data processing, or specific operations.

Note: Scripts may be executed without loading into context, but can still be read by Claude for patching or environment adjustments.

references/

Documentation and reference material intended to be loaded into context to inform Claude's process and thinking.

Examples from other skills:

• Product management: communication.md, context_building.md - detailed workflow guides
• BigQuery: API reference documentation and query examples
• Finance: Schema documentation, company policies

Appropriate for: In-depth documentation, API references, database schemas, comprehensive guides, or any detailed information that Claude should reference while working.

assets/

Files not intended to be loaded into context, but rather used within the output Claude produces.

Examples from other skills:

• Brand styling: PowerPoint template files (.pptx), logo files
• Frontend builder: HTML/React boilerplate project directories
• Typography: Font files (.ttf, .woff2)

Appropriate for: Templates, boilerplate code, document templates, images, icons, fonts, or any files meant to be copied or used in the final output.

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Any unneeded directories can be deleted. Not every skill requires all three types of resources.