Root (chord)

Root (chord)

In music theory, the root of a chord (in French, basse fondamentale) is the note or pitch upon which a chord may be built by stacking thirds. For example, a three-note triad using C as a root would be C-E-G. Conventionally, the name of the root note denotes the chord. Thus, a major chord built upon C is called a C major chord. The root is often confused with the tonic, which is the reference note of a scale, rather than that of a chord.

While the theory of chordal roots describes bottom-up construction of chords, chords appearing in musical scores or performances will not always use the chordal root as the lowest pitch. When a chord's bass note is its root, the chord is said to be in root position or in normal form. When the root is not the lowest pitch played in a chord, it is said to be inverted. Consequently, changing the configuration of pitches above a given bass note will typically result in a new note becoming the root.

A major scale contains seven unique pitch classes, each of which might serve as the root of a chord: