The chromatic scale is a musical scale that contains all twelve pitches of the Western tempered scale. All of the other scales in traditional Western music are subsets of this scale. Each pitch is separated from its upper and lower neighbors by the interval of one half step, or semitone. In tonal music this scale finds little use outside of decorative runs up or down as it has no harmonic direction, and thus it may seen as the basis of music written using the twelve tone technique, a tone row being a specific ordering or series of the chromatic scale.