# Chord Substitution Finder MCP

> Chord Substitution Finder instantly identifies harmonic alternatives and deep-dives into musical tension within any chord progression. Use this MCP to explore Tritone, Diatonic, Relative, Parallel, and Chromatic Mediant substitutions for single chords or full sequences. You'll analyze exactly how each theoretical change affects the harmony and overall emotional movement of your music.

## Overview
- **Category:** music-theory
- **Price:** Free
- **Tags:** harmony, chords, musicology, composition, jazz-theory

## Description

When you’re writing a piece, sometimes the chord progression feels stuck. This MCP acts like an instant theory textbook that knows when to suggest a better way forward. Instead of flipping through books or remembering complex rules, you feed it your chords, and it shows you dozens of viable substitutions. You can explore every type of harmonic change—from simple relative swaps to highly dramatic chromatic movements. It doesn't just give names; it analyzes the tension arc of the whole progression, telling you if the movement is building too fast or dragging in the wrong spot. Because Vinkius hosts this MCP, your agent gets access to a massive catalog of tools, making sure that when you need musical insight, you find it instantly.

## Tools

### analyze_progression_tension
Analyzes a full string of chords to measure how the harmonic tension builds and releases across the sequence.

### get_substitution_detail
Provides an in-depth definition and explanation for any specific chord substitution type you ask about.

### find_substitutions
Identifies all available harmonic replacements for a single starting chord, covering several theoretical methods.

## Prompt Examples

**Prompt:** 
```
Find substitutions for G7.
```

**Response:** 
```
Running `find_substitutions` for G7... Found Tritone substitution: Db7, which increases tension and creates chromatic movement.
```

**Prompt:** 
```
Analyze the tension of [Cmaj7, Am7, Dm7, G7].
```

**Response:** 
```
Using `analyze_progression_tension`... The progression starts with Low tension (Cmaj7) and moves through Medium tension to a High tension dominant (G7).
```

**Prompt:** 
```
What is a Tritone substitution?
```

**Response:** 
```
According to `get_substitution_detail`, a Tritone substitution replaces a dominant seventh chord with another dominant seventh chord an augmented fourth away.
```

## Capabilities

### Explore alternate chords
It finds multiple chord substitutions for any single chord you provide.

### Map harmonic tension
You can analyze a full sequence of chords to see exactly where the musical tension peaks and dips.

### Understand theory terms
Get detailed breakdowns, like defining what a Tritone substitution actually is in practice.

## Use Cases

### The Bridge Feels Predictable
A composer realizes the middle section (bridge) is too safe. They ask their agent to run find_substitutions on the key chords, discovering a dramatic chromatic mediant swap that instantly gives the piece more tension and movement.

### Checking Chord Flow
A jazz arranger types in a sequence of 16 bars. They ask the agent to analyze_progression_tension. The report shows the progression is flatlining, prompting them to add chords that build up tension leading into the final chorus.

### Learning New Theory
A student needs to know how a Tritone substitution works in practice. They use get_substitution_detail and get an immediate, clear explanation of the theory without reading a textbook chapter.

## Benefits

- Instantaneous alternatives: Don't get stuck on a chord. Use find_substitutions to see dozens of options—Tritone, Diatonic, Relative—in seconds.
- Understand movement: analyze_progression_tension grades your entire song structure, showing you exactly when the tension peaks so you know where to put the big moment.
- Deep theory knowledge: If a concept confuses you, use get_substitution_detail. It breaks down complex ideas like 'what is a chromatic mediant' into plain language.
- Genre flexibility: This MCP works for jazz harmony or classical pop progressions; it doesn't care about the style, just the chords.
- Time savings: You cut out hours of reference book flipping and Google searches. Your agent handles the heavy lifting so you can focus on writing.

## How It Works

The bottom line is you get actionable musical data that tells you how to make your chords sound better.

1. Input the chord or progression you want to analyze into your AI client.
2. The MCP processes the data by comparing it against established music theory rules, generating potential substitutions and tension analyses.
3. You receive a structured report showing viable alternatives, along with a clear grade of harmonic movement (low, medium, high tension) for the entire sequence.

## Frequently Asked Questions

**How does the Chord Substitution Finder MCP work with jazz chords?**
It handles complex extensions and alterations common in jazz. You can input specific voicings like Cmaj13 or G7alt, and it will find relevant substitutions that fit those advanced harmonic structures.

**Does this MCP only work for major keys?**
No, the engine supports all key signatures. You can analyze minor, modal, or even mixed-mode progressions, finding appropriate substitutes across the entire chromatic spectrum.

**Can I use find_substitutions to fix a bad section of music?**
Yes. Identify the chord that feels wrong in your piece and run find_substitutions on it. The resulting alternatives provide immediate, theoretically sound replacements you can test out.

**What is the difference between analyze_progression_tension and find_substitutions?**
analyze_progression_tension looks at your chords to grade the overall emotional movement (the arc). find_substitutions focuses only on giving you alternatives for one specific chord.

**Is this MCP useful for film scoring?**
Absolutely. Film scores often rely heavily on harmonic shifts to signal a plot change or increase drama; this MCP gives you the theoretical tools to execute those dramatic chord changes effectively.