What is a Chord?

A chord is three or more notes played simultaneously. For bass players, the most fundamental chord type is the triad — three notes stacked in thirds. Every triad has a root (the note that names the chord), a third (which determines major or minor quality), and a fifth (which provides stability).

For example, a C major triad consists of C (the root), E (a major third above C), and G (a perfect fifth above C). Play these three notes — as a block chord on piano, or as an arpeggio one note at a time on bass — and you hear the bright, open sound of C major. Change the E to E♭ and you get C minor — a darker, more introspective sound from a single note change.

Triads are the building blocks of all harmony in Western music. On bass you will rarely strum all three notes at once, but every bass line, arpeggio, and groove traces back to the triad of the chord underneath it. Understanding this foundation unlocks the entire chord vocabulary.