Polytonality
（重定向自Polyharmony）
![Example of C and F sharp major chords together in Stravinsky's Petrushka (see: Petrushka chord). Play](/Images/godic/202502/03/Stravinsky-petrushka-fanfare4439.png")
![Mozart used polytonality in his A Musical Joke for comic effect. Play](/Images/godic/202502/03/K522_multitonality4439.png")
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![Example of polytonality or extended tonality from Milhaud's Saudades do Brasil (1920) Play , right hand in B major and left hand in G major, or both hands in extended G major (Leeuw 2005, 87).](/Images/godic/202502/03/Milhaud_-_Saudades_do_Brazil_polytonality4439.png")
Polytonality (also polyharmony (Cole and Schwartz 2012)) is the musical use of more than one key simultaneously. Bitonality is the use of only two different keys at the same time. Polyvalence is the use of more than one harmonic function, from the same key, at the same time (Leeuw 2005, 87).