What a piano chord is
A chord combines notes heard as one harmonic unit. Start with a chord quality, then explore every root and inversion.
A chord is an organised set of pitch roles heard together or understood as one harmony. The simplest reference structures here are triads: root, third and fifth. Larger qualities may add sixths, sevenths or ninths; suspended structures replace the third. The keyboard shows pitch location, while formula and spelling explain why the notes have those names.
Read the anatomy of a chord symbol
Begin with the root letter and accidental, then read quality, extension or addition, alteration, omission and slash bass in that order. C means a C-major triad; Cm changes the third; C7 adds a minor seventh to the major triad; Cmaj7 instead adds a major seventh; C/E requests E in the bass.
A symbol is compact instructions, not a fixed hand shape. Expand it into a formula and written note list before deciding the register, spacing and doubling that suit a particular use.
Quality comparison matrix
Major, minor, diminished and augmented triads differ at the third and fifth. Suspended chords replace the third with degree two or four. Sixth chords add degree six, seventh chords specify a seventh quality, and ninth chords extend a seventh-based stack.
With C fixed, compare C–E–G, C–E♭–G, C–E♭–G♭ and C–E–G♯. That sequence isolates the changes defining major, minor, diminished and augmented rather than relying on mood labels.
- major: 1–3–5; C example C–E–G
- minor: 1–♭3–5; C example C–E♭–G
- diminished: 1–♭3–♭5; C example C–E♭–G♭
- augmented: 1–3–♯5; C example C–E–G♯
- suspended second: 1–2–5; C example C–D–G
- suspended fourth: 1–4–5; C example C–F–G
- dominant seventh: 1–3–5–♭7; C example C–E–G–B♭
- major seventh: 1–3–5–7; C example C–E–G–B
- minor seventh: 1–♭3–5–♭7; C example C–E♭–G–B♭
- diminished seventh: 1–♭3–♭5–♭♭7; C example C–E♭–G♭–B𝄫
- half-diminished seventh: 1–♭3–♭5–♭7; C example C–E♭–G♭–B♭
- major sixth: 1–3–5–6; C example C–E–G–A
- minor sixth: 1–♭3–5–6; C example C–E♭–G–A
- add nine: 1–3–5–9; C example C–E–G–D
- major ninth: 1–3–5–7–9; C example C–E–G–B–D
- minor ninth: 1–♭3–5–♭7–9; C example C–E♭–G–B♭–D
- dominant ninth: 1–3–5–♭7–9; C example C–E–G–B♭–D
Triads, sevenths, added notes and extensions
Triads contain three distinct chord roles. Seventh chords add another stacked third and can have major, minor, dominant, diminished or half-diminished combinations. An added-note chord such as Cadd9 includes the triad plus D without implying B♭; C9 normally includes a seventh foundation.
On the piano, extended identities are frequently voiced with omissions or doublings. The reference states the complete formula first, then treats practical voicing as a separate decision so texture does not silently change the chord definition.
Inversions and voicings
Root position places the root in the bass. First inversion places the third there; second inversion the fifth; seventh chords also allow the seventh in the bass. Inversion is therefore a bass relationship.
Voicing describes octave, spacing, order above the bass and duplication. C3–G3–E4 and C3–E4–G4 are different voicings but both root-position C major. Use the inversion explorer to keep identity constant while hearing each bass change.
Enharmonic spelling
D major is D–F♯–A, not D–G♭–A, because the middle chord tone is a third above D and must use an F letter. C augmented ends G♯ rather than A♭ because the altered tone remains a fifth. Equal-temperament keys can coincide while their written functions differ.
ChordMetric assigns degree letters before calculating accidentals. This makes the text answer more than a cosmetic label for a keyboard shape and allows chord, scale and key pages to share one central spelling model.
How to use the explorer and finder
Use the explorer when you know a root and quality. Change one selector, compare formula and notes, rotate inversions, play together or as an arpeggio, then copy or print the visible answer. Follow the result into its root hub or a relevant key.
Use the reverse finder when you know two to six pitch classes. Exact sets are separated from partial supersets, and an explicit bass can describe inversion. Several names may remain plausible because pitch-class identity alone does not prove harmonic function.
Four worked comparisons
C major versus C minor changes E to E♭. D major versus D diminished changes F♯ to F and A to A♭. G7 versus Gmaj7 changes F to F♯. Csus4 versus Cadd4 is not a harmless wording swap: suspension replaces the third, while an added fourth can retain it.
Transpose each comparison to E♭ and write the letters before checking pitches. Then move the lowest tone of each chord above the others and name the new inversion from the bass.
- C–E–G → C–E♭–G: lower degree 3.
- D–F♯–A → D–F–A♭: lower degrees 3 and 5.
- G–B–D–F → G–B–D–F♯: raise degree 7.
- C–F–G versus C–E–F–G: replacement versus addition.
Read keyboard diagrams and print safely
Every selected key is repeated in text, so colour and audio are not required. Read notes from bass upward, reduce octave duplicates to identify the pitch-class set, then compare the bass with the root. The print view retains formulas, names and status while removing navigation and playback controls.
Browse all roots and qualities through stateful explorer controls or open the complete chord chart. Enharmonic pairs remain selectable without publishing duplicate keyboard-content routes.
Continue learning
Use the chord explorer to change the root, quality and bass note, or open the finder when you already know the pitches. Methodology and Sources explains the note-spelling conventions used throughout ChordMetric.