THIRI Chord Intelligence — Music Theory MCP Server

Deterministic Music Theory for Claude, Cursor, and Autonomous AI Agents Large Language Models (LLMs) frequently hallucinate music theory, leading to incorrect…

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What it can do

  • Analyze Chord: Parse a chord into root, quality, intervals, and (with a key) roman numeral + function.
  • Resolve Chord: Resolve a chord to spelled notes, frequencies, MIDI, and recommended scales.
  • Generate Voicing: Instrument-ready voicing in a style; pass previousNotes for a voice-leading score.

What data it sees

Do you need an account

An API key from the service settings is required

Deterministic Music Theory for Claude, Cursor, and Autonomous AI Agents

Large Language Models (LLMs) frequently hallucinate music theory, leading to incorrect notes, false Roman numerals, and broken voice leading. THIRI solves this by providing a deterministic, mathematical music-theory engine (pitch-class-set theory over ℤ/12) directly to your AI.

It gives AI assistants precise, reproducible harmonic reasoning in milliseconds, allowing them to write correct musical scores, analyze progressions, and generate playable arrangements.

🎷 Key Features:

  • Chord Analysis (analyze_chord): Parse any symbol (e.g., Cmaj7/E, G7#11) to retrieve root, quality, intervals, Roman numerals, and diatonic or chromatic harmonic functions.
  • Note Resolution (resolve_chord): Resolve chord symbols to spelled notes (enharmonically correct), frequencies (Hz), MIDI numbers, and scale recommendations.
  • Voicing Engine (generate_voicing): Generate instrument-ready voicings (rootless, shell, triad, pad, drop-2, drop-3) and calculate voice-leading scores for transitions.
  • Reharmonization (reharmonize): Substitute progressions using classic jazz techniques, including Tritone Substitution, ii-V Insertion, Modal Interchange, Coltrane Changes, and Backdoor cadences.

Ideal for developers building AI music assistants, digital audio workstation (DAW) agents, educational theory tools, and automated composition workflows.

Server tool list (4)

Raw names from tools/list. Only developers need these.

analyze_chordParse a chord into root, quality, intervals, and (with a key) roman numeral + function.
resolve_chordResolve a chord to spelled notes, frequencies, MIDI, and recommended scales.
generate_voicingInstrument-ready voicing in a style; pass previousNotes for a voice-leading score.
reharmonizeReharmonize a progression. Techniques: tritone_sub, ii_v_insertion, modal_interchange, diminished_passing, secondary_dominant, chain_of_dominants, coltrane_changes, backdoor (or auto).