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Chord Theory

Diatonic Chord Reference

Choose a key and see its diatonic chords instantly. Compare triads and seventh chords by ear, then use them for songwriting or progression practice.

Key
Open in chord progression player →See this key's scale →How to use ↓
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Select a chord below to see its notes on piano or guitar.

What is this tool?

See and hear the 7 chords that naturally fit any key. Each chord is color-coded by its function — T (tonic), SD (subdominant), or D (dominant) — so you can instantly grasp the role every chord plays in a song.

When it helps

  • Starting point for songwriting

    Pick a key and the 7 usable chords appear. Arrange them in any order and you already have a progression.

  • Learn chord functions by ear

    Tap any chord to hear it. The T / SD / D color coding helps you internalize the feel of stability, motion, and tension.

  • Help with ear training & covers

    Once you know the song's key, most of its chords will fall within these 7 — narrowing the possibilities makes transcribing much easier.

How to use

  1. 1 Pick the song's key (C, G, D, ...) from the Key selector at the top.
  2. 2 Toggle Major / Minor to match the mood you're after.
  3. 3 Switch between Triad / Seventh to try simple vs. jazzier voicings.
  4. 4 Tap any chord card to hear it — the keyboard below highlights its notes.
  5. 5 Explore further with the Circle of Fifths or Chord Progression Player.

Related Tools

🔍Chord Finder ▶Chord Progression Player 🔄Transpose Tool ⭕Circle of Fifths

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