In this guide
A chord is a group of notes heard as a harmonic unit. A basic major or minor triad has a root, third and fifth; changing the third changes its quality. Chords can be played together or sounded as a broken chord.
A chord in music is a group of notes heard as a harmonic unit. A common example is C major: play C, E and G together on a keyboard or instrument and you hear a three-note chord called a triad.
Chords often accompany a melody, but they can also form part of the musical foreground. Their notes can be struck together or played one after another as a broken chord or arpeggio. Chord labels describe note relationships; the instrument, rhythm and arrangement affect how a chord sounds.
Build a basic chord: C major
A major triad contains a root, a major third and a perfect fifth above the root. For C major:
| Role | Note | Distance above C |
|---|---|---|
| Root | C | Starting note |
| Third | E | Four semitones |
| Fifth | G | Seven semitones |
- Find a C on a piano or other instrument, then find the E and G above it.
- Play C–E–G together. Then play the same notes separately in that order; the second version is a broken chord.
- Keep C and G, but lower E by one semitone to E♭. C–E♭–G is a C minor triad.
- Alternate the two at a similar level and pace. Listen for the change in the middle note.
In this example, C major has a major third from C to E; C minor has a minor third from C to E♭. Both retain a perfect fifth from C to G. The Open University's triad lesson explains how stacked thirds form these chords.
Common chord types
| Chord | Example notes | What changes |
|---|---|---|
| Major triad | C E G | Major third and perfect fifth above C. |
| Minor triad | C E♭ G | Minor third and perfect fifth above C. |
| Diminished triad | C E♭ G♭ | Minor third and diminished fifth above C. |
| C major seventh | C E G B | Adds a major seventh to the C major triad. |
These examples start on C so you can compare them. Musicians can build chords on other roots and arrange or double their notes in different registers. Some contexts call two-note combinations, such as guitar power chords, chords as well; the triads above are a useful starting point, not the only possible vocabulary.
What is a chord progression?
A chord progression is a sequence of chords over time. For a simple C-major example, play C major → F major → G major → C major:
- C major: C–E–G
- F major: F–A–C
- G major: G–B–D
- Return to C major: C–E–G
Try one chord per measure in a comfortable tempo. The rhythm, register and arrangement can change the result even when the chord sequence stays the same. The final C can sound like a return to the tonal center in this example, but not every progression ends on its home chord.
Chords, keys and scales
A scale is an ordered collection of notes; a chord combines notes as a harmonic unit; a key describes a tonal center and the relationships around it. In C major, the C major scale provides notes for several common chords, including C major, F major and G major. A piece can also use chords or notes outside the basic scale.
For the larger context, see what a musical key is and what a scale is. The song key finder estimates major and minor key candidates from a supported local audio section; it does not identify every chord. Check its suggestions against the recording.
What is a chord inversion?
An inversion changes which chord tone is the lowest note. A C major triad in root position has C as its lowest note. E–G–C places E lowest and is a first inversion; G–C–E places G lowest and is a second inversion. All use the same three pitch names, but the voicing and bass note change.
When arranging or transposing music, check how the whole chord moves. The key-change guide shows how a uniform semitone shift changes the key while preserving interval relationships; shifting a finished audio mix does not provide separate control of each chord tone.
Common questions
How many notes are in a chord?
A triad has three distinct chord tones, and seventh chords have four. Musical usage varies, and some two-note combinations are also called chords.
Is a chord the same as a melody?
No. A melody is a musical line unfolding over time; a chord is a group of notes heard as a harmonic unit. An arrangement can contain both.
Are all chords in a major key major?
No. A major key commonly contains both major and minor diatonic triads, and music can use other chords as well.