POLYTONAL MUSIC:

Polytonality is the simultaneous use of two or more different keys or scales and is generally employed to create tonal conflict. A great source for new sounds but more so than not, will tend to give a feeling of unrest as the two or more different scale tones clash in their passing. The simultaneous combination of two or more key-centred melodies may be performed in such a way as to at times diatonically emphasize any one of the combined keys or even be performed separately as independent key-centred melodies.