Chord Progression Analyzer – What Progression Is This?

Analyze Any Chord Progression with Harmonic Theory

A Chord Progression Analyzer helps you understand how a chord sequence works instead of simply displaying the chords themselves. Paste a progression using standard chord symbols, and the analyzer detects the most likely key and scale mode, assigns Roman numerals, identifies harmonic functions, and highlights non-diatonic harmony such as secondary dominants, borrowed chords, and modal interchange.

The tool is useful for songwriters studying popular songs, musicians learning harmony, producers analyzing references, and students exploring functional music theory. It also includes browser-based audio playback, interactive piano and guitar visualizers, cadence detection, tension analysis, and MIDI export for use in compatible digital audio workstations.

How to Use the Chord Progression Analyzer

Using the analyzer is straightforward:

1. Enter a chord progression using standard chord symbols such as C G Am F, Cmaj7 | Dm7 | G7 | C, or slash chords like C/G.
2. Select a progression preset if you want to experiment with common harmonic patterns.
3. Choose the automatic key analysis mode or manually select a preferred scale mode when needed.
4. Click the analyze button to generate the harmonic breakdown.
5. Preview the progression using the built-in audio player with adjustable tempo, looping, and multiple instrument sounds.
6. Review the detected key, Roman numerals, cadence, harmonic functions, tension movement, and suggested reharmonization ideas.
7. Export the analyzed progression as a Standard MIDI (.mid) file or generate a shareable link.

If you need to build a progression from scratch before analyzing it, the Chord Progression Calculator provides an interactive workflow for creating diatonic progressions

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What the Analysis Results Mean

The analyzer evaluates the progression from several musical perspectives.

Analysis	Description
Key Detection	Finds the most likely key and supported scale mode with confidence scoring.
Roman Numerals	Labels each chord according to its scale degree.
Harmonic Function	Identifies tonic, subdominant, and dominant functions.
Chord Notes	Displays the pitches contained in each chord.
Cadence Detection	Recognizes common harmonic endings such as authentic, plagal, or deceptive cadences.
Harmonic Patterns	Identifies recognizable songwriting progressions and movement.

Roman numerals make it easy to compare progressions across different keys because the harmonic relationships remain the same after transposition. If you’d like to practice reading these symbols, the Roman Numeral Converter explains how chord symbols translate into functional harmony.

Detect Borrowed Chords and Secondary Dominants

Many songs include chords that fall outside the basic diatonic scale.

The analyzer identifies several common harmonic devices, including:

• Secondary dominants such as V/V or V/vi.
• Borrowed chords from parallel major or minor keys.
• Modal interchange.
• Chromatic passing harmony when supported by the progression.

These harmonic colors often create stronger tension, smoother transitions, or a distinctive emotional character while still resolving naturally within the progression.

For a deeper explanation of functional harmony, the article Roman Numeral Chords provides additional theory and practical examples.

Preview, Visualize, and Export Your Progression

The analyzer includes several tools that help you hear and understand the progression.

Audio playback is handled through your browser using the Web Audio API, allowing you to preview the chords with multiple instrument timbres while adjusting playback speed between 40 and 220 BPM.

The visual section displays:

• A two-octave piano keyboard.
• Standard six-string guitar fretboard diagrams.
• Harmonic tension flow visualization.
• Reharmonization ideas generated from the analyzed progression.

After reviewing the results, you can export the progression as a Standard MIDI (.mid) file. MIDI generation occurs directly inside the browser, making it easy to drag the exported file into compatible DAWs for arranging, orchestration, or production work.

If you’re looking for fresh songwriting inspiration instead of analyzing an existing sequence, try the Random Chord Progression tool.

Tips for Better Harmonic Analysis

For the most accurate results:

• Enter standard chord symbols with correct accidentals.
• Separate chords using spaces, bars, or hyphens for readability.
• Include chord qualities such as maj7, m7, or 7 when appropriate.
• Analyze the complete progression rather than isolated chords whenever possible.
• Compare multiple detected keys if the confidence scores are close, especially for modal music.
• Listen to the playback while reviewing the Roman numeral analysis to connect theory with sound.

If you’re writing original songs, the guide How to Write Chord Progressions offers practical songwriting techniques, while the MIDI Chord Generator can help expand your production workflow.

What is a chord progression analyzer?

A chord progression analyzer is a music theory tool that examines a sequence of chords to determine its likely key, scale mode, Roman numerals, harmonic functions, and other theoretical characteristics.

Can the analyzer detect the key automatically?

Yes. It evaluates supported keys and scale modes, then ranks the most likely matches using confidence scores based on the entered progression.

Does it recognize borrowed chords?

Yes. The analyzer can identify borrowed chords, modal interchange, and supported secondary dominants that fall outside the primary diatonic harmony.

Can I export the analyzed progression as MIDI?

Yes. The tool generates a Standard MIDI (.mid) file directly in your browser for use in compatible digital audio workstations.

What chord formats are supported?

The analyzer accepts common chord symbols including major, minor, seventh chords, slash chords, and progressions separated by spaces, bars, or hyphens.