Polyphony is the multiplicity of different sounds played in harmony rhythm.
Polyphonic sounds are the opposite of monophonic ones, which are characterized by reproducing only one voice or sound instrument.
As a musical technique, polyphony developed mainly during the so-called "Late Middle Ages" and Renaissance, when classical music started to be composed by the alternation between different voices on a base rhythmic.
See also: the meaning of Classic music.
Etymologically, the word "polyphony" originated from the Greek polluphonies, which can be translated as “sound of many instruments or voices”.
textual polyphony
In the linguistic studies of Russian philosopher Mikhail Bakhtin, polyphony consists of diversity of different lines and concepts present in the same literary work, especially when there is the presence of voices with divergent or controversial speeches.
Polyphony and Intertextuality
From the concept of textual polyphony developed by Bakhtin, this is intrinsically related to the intertextuality, as there is a reference to different external dialogues (from other works) inserted in a given text, for example.