An octave in music consists of eight notes. In Western music, an octave is defined as the interval between one musical pitch and another with half or double its frequency. For example, if a note has a frequency of 440 Hz, the note one octave higher would have a frequency of 880 Hz. The notes in an octave follow the pattern of the musical scale, which includes the sequence of whole and half steps, creating a variety of harmonies and melodies. This structure is fundamental to music theory and composition.