
Harmonic Analysis & Composition Assistant for Classical Music
Analyze harmonic progressions, voice-leading, and classical composition structure with Claude
What You Can Do
You can submit harmonic progressions, score excerpts, or compositional sketches for detailed analysis using functional harmony labels, voice-leading rules, and period-appropriate conventions. Claude identifies harmonic functions, detects counterpoint violations like parallel fifths, suggests voice-leading solutions, and helps diagnose structural weaknesses in multi-movement works.
Features
Identify and label chord functions (I, IV, V, vi) with harmonic context and role within the phrase structure
Detect parallel fifths, awkward leaps, poor resolutions, and counterpoint rule violations with specific corrections
Analyze authentic, plagal, deceptive, and half cadences with harmonic rhythm analysis
Explore alternative progressions within baroque, classical, or romantic stylistic constraints
Outline tonal areas, key relationships, and harmonic architecture for multi-movement structures
Verify that progressions, voice leading, and structural choices follow period-appropriate practices
Identify why passages sound awkward harmonically or structurally with targeted solutions
Receive formatted analysis suitable for marking up scores or manuscripts with harmonic labels
Example Output
Input: A four-bar progression in C major: C-Am-F-G
Output:
- Measure 1: C major (I) — tonic establishment
- Measure 2: A minor (vi) — relative minor, extends tonic function
- Measure 3: F major (IV) — subdominant, prepares dominant
- Measure 4: G major (V) — dominant, requests resolution
Voice-Leading Check: Soprano leap from E to G in m.2 creates awkward interval; recommend stepwise motion or tied note.
Harmonic Function: Strong pre-cadential motion with typical IV-V approach cadence. Add I resolution in m.5 for authentic cadence.
Input: String quartet exposition needing key modulation from G major to D major
Output:
- Suggested pivot chord: D minor (vi in G, iv in D) at m.12
- Alternative: Direct V/V preparation (A7 chord) for dramatic modulation
- Voice-leading recommendation: Hold G in first violin across pivot to ensure smooth transition
- Structural note: Establish secondary dominant by m.14 to confirm D major tonality
What's Included
- SKILL.md: Complete skill instruction file with usage guidelines and framework overview
- Harmonic Analysis Template: Formatted score analysis worksheet with functional labels, voice-leading checklist, and diagnostic notes
- Classical Progressions Reference: Common baroque, classical, and romantic harmonic patterns with voice-leading solutions
- Voice-Leading Rules Checklist: Quick-reference guide for counterpoint violations (parallel fifths, leading-tone resolution, leap management)
- Sonata Form Harmonic Roadmap: Key area planning framework for exposition, development, and recapitulation with tonal relationships
Who It's For
- Classical composers and songwriters working in baroque, classical, or romantic idioms
- Music theory students and educators teaching functional harmony and form analysis
- String quartet and choral arrangers refining voice-leading and harmonic coherence
- Score analysts and musicologists examining compositional techniques in classical works
- Orchestral arrangers planning harmonic architecture and key relationships across movements
Best For
- Analyzing harmonic progressions with functional harmony labels and period-appropriate conventions
- Diagnosing and correcting voice-leading issues like parallel fifths, poor resolutions, and awkward leaps
- Planning harmonic architecture for multi-movement works like sonatas and string quartets
- Exploring harmonic alternatives within specific stylistic and tonal constraints
- Verifying cadential structures and understanding their function within phrase and formal design







