By creating smooth sentence fluency that has rhythm when read aloud
The switch in the narration emphasizes the contrast between Nero's high opinion of his musical ability and the opinion of a competent observer. Despite Policles's forceful manner, we value his viewpoint because he is passionate about music, a gifted singer, and doesn’t realize Nero is the emperor. When the narration follows Policles, we see how repulsive Nero is as a singer and a person. The narration emphasizes how unjust and ridiculous the contest was and shows that power matters most under many circumstances.
When the narration follows Nero and Platus, we get a glimpse of Nero's extreme conceit. We're also left with a sense that it would be impossible for anyone to change his opinion. Instead, the people around Nero make extraordinary efforts to pretend they share his inaccurate views. This view of Nero and Platus reveals another theme of the story: people can irrationally justify almost anything. Also, this narrative view supports the audience’s false applause for Nero as well as Policles's chaotic escape.
