polytonality

The simultaneous sounding of two or more keys. Bartók used bitonal textures extensively, especially in the 14 Bagatelles (Op. 6) where different key signatures appear in each hand. Rather than producing atonal chaos, Bartók's polytonality typically creates a specific kind of shimmering tension between two clearly audible tonal centres.

In bitonal passages, try to hear and project each hand's tonal identity clearly, rather than blending them into a single muddy texture. The tension between the two keys is the expressive content.