Much of the harmony of chromatic tonal music can be analyzed by using the same vocabulary for altered chords, modulations, chromatic nonchord tones. "The critical distinction between the two styles lies in the transformation of the diatonic scalar material of the classical tonal system into the equally-tempered twelve note chromatic complex of the diatonic tonal system." The decline of the tonal system as the primary organizing force in music coincided with and was largely due to the ascendancy of chromaticism. Diatonic tonal music is essentially diatonic on all levels, whereas chromatic tonal music is based to a much greater extent on the chromatic scale. More specifically, it refers to the systematic avoidance of most of those musical materials and devices that traditionally have been used to define a tonal center. Atonal music avoids the use of most of those musical materials and devices that traditionally have been used to define a tonal center.