Octave (theory)

An octave is a fundamental concept in music theory that describes the interval between one musical pitch and another with twice or half its frequency. For example, if a note vibrates at 440 Hz, the note one octave higher vibrates at 880 Hz, and one octave lower at 220 Hz. This interval sounds similar but higher or lower in pitch. Octaves are natural relationships that create musical harmony and are used to organize pitches across scales and instruments, contributing to the perception of pitch similarity and musical structure.