The Emperor is annoyed that the crowd routinely chant out of step at the Empire's largest circular amphitheatre. For example, they are supposed to shout phrases in unison such as "Hail to the Emperor, he is great!" and yet they always sound like a rabble.
All powerful though he may be, he realises he can't punish the whole crowd at every event. Bread and circuses and all that.
Nevertheless he decides that just for once on his next birthday his Court Musician must arrange an event where he trains a crowd of people (the chorus) to occupy the front few rows of the arena's seats and chant a spoken birthday ode to him in perfect time.
How does the Court Musician keep everyone in time?
Why does he equip everyone in the chorus with earplugs?
Where is the only place for the Emperor's throne and why?