Editing Polytonality (section)

{{Short description|Simultaneous use of multiple musical keys}}
{{Distinguish|Polyphony}}
'''Polytonality''' (also '''polyharmony'''{{sfn|Cole and Schwartz|2012}}) is the [[music]]al use of more than one [[key (music)|key]] [[simultaneity (music)|simultaneously]]. '''Bitonality''' is the use of only two different keys at the same time. '''Polyvalence''' or '''polyvalency''' is the use of more than one [[diatonic function|harmonic function]], from the same key, at the same time.{{sfn|Leeuw|2005|loc=87}}
[[File:Stravinsky-petrushka-fanfare.png|thumb|upright=1.5|Example of C- and F-sharp major chords together in Stravinsky's ''[[Petrushka (ballet)|Petrushka]]'' (see: [[Petrushka chord]])[[File:Stravinsky-petrushka-fanfare.mid]]]]

Some examples of bitonality superimpose fully [[harmony|harmonized]] sections of music in different keys.