Understanding Chords
A chord is three or more notes sounding together. Change the notes you stack and you change the emotional color of the sound — from joyful major triads to dark minor sevenths to unresolved sus chords. Here's what each quality means and how to use the controls.
The three triad families
Major (maj) stacks a major third (4 semitones) and a minor third (3 semitones) — 0, 4, 7. Bright, resolved, happy. Minor (min) flips the order — minor third on the bottom, major on top — 0, 3, 7. Sadder, pensive. Diminished (dim) stacks two minor thirds — 0, 3, 6. Tense, unresolved, wants to move somewhere. Augmented (aug) stacks two major thirds — 0, 4, 8. Dreamlike, suspended, every note feels equal.
The suspended chords
Sus2 replaces the third with a second (0, 2, 7) — open, airy, modern. Sus4 replaces the third with a fourth (0, 5, 7) — classic rock chord before the resolution back to major. Sus chords are ambiguous — neither major nor minor — and typically resolve to a triad.
Seventh chords — adding color
Stack a seventh on any triad and you get a richer, more sophisticated sound. Maj7 (0, 4, 7, 11) is jazz-smooth and dreamy — the first chord of "The Girl From Ipanema." Min7 (0, 3, 7, 10) is mellow and reflective — endless R&B, soul, neo-soul. Dom7 (0, 4, 7, 10) is the blues and funk chord — bright major with a tension that wants to resolve down a fifth. Dim7 (0, 3, 6, 9) is the most tense of all, used in classical and horror film scoring. M7b5 (half-diminished, 0, 3, 6, 10) is a jazz staple.
Extended chords — ninths and beyond
Maj9, Min9, Add9 stack the ninth note on top of the triad or seventh chord. Nines add a lush, cinematic, slightly ambiguous color without the intensity of the seventh alone. Used constantly in gospel, pop ballads, and modern jazz.
Inversions — changing the bottom note
A C major chord is C-E-G. In first inversion, E is on the bottom: E-G-C. In second inversion, G is on the bottom: G-C-E. The chord is still "C major," but the voicing changes — first inversion sounds more plaintive, second inversion sounds more rooted in the 5th, ready to resolve. Inversions are how professional composers create smooth voice-leading between chords (the bottom note doesn't have to jump a huge distance every chord change).
Strum mode
Chords played on piano sound simultaneously — all notes hit at once. Chords played on guitar sound slightly staggered — the pick travels across strings over roughly 30-80 milliseconds. Strum mode recreates that effect, making chords feel looser, more human, more guitar-like. Turn strum off for crisp piano-style chords, on for acoustic-guitar feel.
About Chord Explorer
Play and explore major, minor, 7th, diminished, augmented, and sus chords on a 2-octave piano keyboard. Free browser-based chord tool — no install required.
How to use
- Choose a root note from the Root Note dropdown — this is the letter name of the chord (C, D, E, F, G, A, or B including sharps).
- Select a chord quality (Major, Minor, Dom 7th, Major 7th, Minor 7th, Diminished, Augmented, Sus 4, Sus 2, or Add 9) to define the character of the chord.
- Press Play Chord to hear all notes sounding together, or Arpeggiate to hear each note in sequence from bottom to top.
- Click any key on the piano keyboard directly to set that note as the root and instantly play the chord. Active notes light up in the chosen color.
- Try the presets (C Major, A Minor, G 7th, F Maj7, B Dim, E Aug) to quickly explore different chord types and voicings.
Frequently asked questions
What is a chord and how are they built?
A chord is three or more notes played simultaneously. Western chords are built by stacking thirds — intervals of either 3 or 4 semitones — above a root note. A major triad uses a major third (4 semitones) followed by a minor third (3 semitones), giving you the familiar bright sound. A minor triad reverses this: minor third then major third. This stacking principle extends to 7th chords, 9th chords, and beyond. Understanding this pattern lets you build any chord from any root note — you do not need to memorize chord shapes, just the interval formula.
What is the difference between a major and minor chord?
The only difference is the middle note — the third. A major chord's third sits 4 semitones above the root (a major third). A minor chord's third sits 3 semitones above the root (a minor third). C major is C-E-G; C minor is C-E♭-G. That single semitone shift completely changes the emotional quality: major chords sound happy, open, and resolved, while minor chords sound darker, sadder, or more introspective. Both share the same perfect fifth (7 semitones above root), which gives them their solid, stable foundation.
What are diminished and augmented chords used for?
Diminished chords (root + minor third + diminished fifth = two stacked minor thirds) sound tense and unstable — they appear frequently in classical music as passing chords that resolve to the home key. In pop and jazz, diminished chords often appear as substitutes for dominant 7th chords. Augmented chords (root + major third + augmented fifth = two stacked major thirds) sound mysterious and unresolved — they appear in jazz standards, film scores, and transitions. Both are considered dissonant chords that create tension wanting resolution to a more stable major or minor chord.
What is a sus chord and why does it sound unresolved?
Sus (suspended) chords replace the third with either the second (sus2) or fourth (sus4) scale degree. Without a third, the chord is tonally ambiguous — it is neither major nor minor. Sus4 chords (C-F-G) create strong upward tension that traditionally resolves down to the major chord (C-E-G). Sus2 chords (C-D-G) sound more open and modern. Sus chords are extremely common in pop and rock — think the opening of 'Pinball Wizard' by The Who or countless U2 songs. They let songwriters delay harmonic resolution for emotional effect.
What are 7th chords and when do I use them?
7th chords add a fourth note to a triad — the seventh scale degree above the root. The dominant 7th (e.g. G7 = G-B-D-F) is the most common: it creates strong tension that resolves to the tonic chord and drives harmonic motion in nearly every style of music. The major 7th (Gmaj7 = G-B-D-F#) has a lush, sophisticated quality favored in jazz and bossa nova. The minor 7th (Gm7 = G-B♭-D-F) blends minor's darkness with a smooth 7th color — the backbone of soul, funk, and jazz harmony. Knowing your 7th chords unlocks the vocabulary of most popular music.
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