A chord is defined by the intervals between its simultaneous notes

Evidence

Hearing harmony is basic to music appreciation, and in its basic form, harmony is sustained by means of chords. A chord consists of at least two notes sounding together, and it can be described in terms of the musical intervals between the individual notes that make it up. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 928

Categorization

• DEFINE: Clear formal definition of chord for the psychoacoustic framework this section builds.
• corroborated: 3 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 928