Last session in our
4e game, where the PCs reached the culmination of their competition with an NPC playwright-cum-gladiatorial-arena-owner, whom they had challenged to a play-off. They wrote and performed a play, while he was doing the same, and the creators of the better play won (and got a pig which the PCs had turned into a minor god, but that's another story).
So what we had happen last session was the performance of the play, which turned out to be a combination of a Bollywood musical and blood sport, where the PCs (lacking any theatrical skill) acted their crazy little hearts out while simultaneously dealing with paid hecklers in the audience, changeling assassins disguised as dancers, gnome arcanists sneaking around backstage and zapping people, and the explosive downsides of filling the corpse of a former PC with fireworks and setting him off on stage.
It was awesome!