Three or more pitches sounded simultaneously are known as:

A melody consists of a sequence of notes that are perceived as a single entity, typically played one after the other rather than simultaneously. While melodies can include chords, they do not represent the simultaneous sounding of multiple pitches, which is essential to the definition of a chord.

Frequency refers to the number of cycles per second of a sound wave, determining the pitch of a single note rather than the combination of multiple pitches. It does not pertain to the concept of simultaneous sound, making it irrelevant in the context of defining chords.

A motive is a short musical phrase or figure that is used as a building block in larger compositions. It is typically a single idea or theme rather than a simultaneous combination of pitches, which a chord represents. Thus, a motive cannot encapsulate the concept of three or more sounds played together.

A cadence is a musical phrase that signals the end of a section or piece, often involving a progression of chords. However, a cadence itself does not refer to the simultaneous sounding of three or more pitches; rather, it is a specific harmonic movement in music, distinct from the broader definition of a chord.