noun
polytonality
A music theory term referring to the simultaneous use of two or more keys in a musical composition.
ストラヴィンスキーの作品には多調性がよく見られる。
Polytonality is often seen in Stravinsky's works.
Tonality: the general concept of key organization in music, of which polytonality is a specific type.
Compound of 多 (た, 'many') + 調性 (ちょうせい, 'tonality'), a straightforward calque of the English 'polytonality'.