An octave or perfect octave is the interval between one musical pitch and another with half or double its frequency.
In music, an octave (Latin octavus: eighth) or perfect octave is the interval between one musical pitch and another with half or double its frequency. The octave relationship is a natural phenomenon that has been referred to as the "basic miracle of music", the use of which is "common in most musical systems". It may be derived from the harmonic series as the interval between the first and second harmonics.
