Root (chord)

In music theory, the root of a chord is the note that names and typifies the chord. Tertian chords are named based on (1) their root, (2) their quality (assumed to be major if no quality is named), and (3) their extensions, if any (assumed to be a triad if no extensions are named). For example, a C chord refers to a C major triad, a major triad built on the note C, which is its root.

The root of a tertian chord is the note on which the subsequent thirds are stacked (though on occasion, some of the notes in the stack may be omitted). For instance, the root of the E minor triad is E, independent of the vertical placement of the three notes that compose it (i.e., E, G, and B).