A chord (kɔ́rd) is a series of notes that are played at the same time, in harmony. More specifically, a chord is a series of three or more notes, usually a combination of at least the first note of a key and the third and fifth note of the same key. A basic chord that consists of those three notes is also known as a triad to music theorists; chords can also be described as majors, minors diminished or augmented.