polyphony
simultaneity of points of view and voices within a particular narrative plane
Summary
In literature, polyphony is a feature of narrative, which includes a diversity of simultaneous points of view and voices. Caryl Emerson describes it as "a decentered authorial stance that grants validity to all voices". The concept was introduced by Mikhail Bakhtin, using a metaphor based on the musical term polyphony.
Source: Wikipedia (CC BY-SA).