Definition of polystylism in English:

polystylism

Pronunciation /ˌpɒlɪˈstʌɪlɪz(ə)m/

noun

Music
  • The adoption of a number of different styles, sometimes within the same piece of work; an instance of this.

Origin

1970s; earliest use found in Journal of Aesthetics and Art Criticism. From poly- + style + -ism.