Creation Tool

Chord Progression Builder

Select a key, click chords to build a progression, and hear it play back. Transpose, reorder, and explore diatonic harmony.

Notation

Diatonic Chords

Your Progression

0/8 chords
Click diatonic chords above to build your progression
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Build Better Chord Progressions

The Chord Progression Builder helps you discover and experiment with diatonic harmony. By working within a key, every chord you select naturally fits together — making it easier to create music that sounds intentional and cohesive.

Whether you're a beginner learning the basics of harmony or an experienced musician exploring new key centers, this tool gives you instant feedback through audio playback and visual Roman numeral analysis. Understanding the function of each chord (tonic, dominant, subdominant) is the key to writing better progressions.

Popular Progressions to Try

  • I–V–vi–IV: The most popular pop progression (C–G–Am–F in C major)
  • I–IV–V: The classic blues and rock foundation
  • ii–V–I: The essential jazz turnaround
  • i–VI–III–VII: The iconic minor-key progression
  • I–vi–IV–V: The 1950s doo-wop progression

Relative Minor Keys

Every major key has a relative minor that shares the same notes but centers on a different root. For example, C major's relative minor is A minor — both use the same set of natural notes but with different tonal centers. Try switching between a major key and its relative minor to hear how the emotional character changes while using the same chords.

Progressions Library
Browse 500+ song progressions by genre, key, or numeral
Popular Progressions
See songs using I\u2013V\u2013vi\u2013IV and other progressions
Music Theory Guide
Learn about chord functions and harmony
Virtual Piano
Play the chords you build on an interactive piano

Chord Progression Builder

Embed this chord progression tool on your site. Build, play, and transpose in any key.

Chord Progression Builder — Frequently Asked Questions

Find answers to common questions about our virtual instruments, practice tools, and music theory workspace.

How do I use the Chord Progression Builder?

Select a key from the dropdown, then click any diatonic chord button to add it to your progression.

You can reorder chords with the up/down arrows, remove them with the X button, and transpose the entire progression up or down by semitones.

What are diatonic chords?

Diatonic chords are chords built from the notes of a particular key or scale.

In a major key, the diatonic chords are: I (major), ii (minor), iii (minor), IV (major), V (major), vi (minor), and vii° (diminished). These chords naturally sound good together because they share the same scale.

How does the playback work?

Each chord is played as an arpeggiated strum (notes played 40ms apart from lowest to highest) using Web Audio API synthesis.

Chords advance at the tempo you select. The currently playing chord is highlighted in green with a visual progress bar.

Can I change the tempo of playback?

Yes.

Use the BPM slider (60–180 BPM) to control how fast the progression plays. Higher BPM values make the chords change faster, lower values give you more time between each chord change.

What do the Roman numerals mean?

Roman numerals indicate the harmonic function of each chord within the key.

Uppercase (I, IV, V) = major chords, lowercase (ii, iii, vi) = minor chords, lowercase with ° (vii°) = diminished. This system helps you analyze and compare progressions across different keys.

How do I transpose a progression?

Use the transpose buttons (+/− semitones) to shift your entire progression up or down.

All chord roots change by the same number of semitones while keeping the same chord qualities and Roman numeral relationships.

What's the difference between sharp and flat notation?

Some keys naturally use sharps (like G major has F#) while others use flats (like F major has Bb).

The toggle lets you display chord names using either convention — sharps for keys like G, D, A, E, and flats for keys like F, Bb, Eb, Ab, Db.