In music, a chord is a group of three or more notes played simultaneously, typically consisting of a root note, a third, and a fifth. Chords are the building blocks of harmony and form the harmonic foundation of a piece of music. They can be major, minor, diminished, augmented, or extended, depending on the intervals between the notes and their arrangement. Chords provide the harmonic support and coloration that accompany melodies and contribute to the overall sound and mood of a musical composition. For many practical and theoretical purposes, arpeggios and other types of broken chords may also be considered as chords in the right musical context.

An arpeggio is a type of broken chord in which the notes that compose a chord are individually sounded in a progressive rising or descending order. Arpeggios on keyboard instruments may be called rolled chords.