When Neil Patrick Harris hosted the 2009 Tony Awards, he closed the ceremony by singing a song (to the tune of 'Tonight' and 'Luck Be a Lady'), the lyrics of which were just one variation based on the winners that had just been revealed that night. The lyricists (Mark Shaiman and Scott Wittman) had come up with lyrics for several possible winning scenarios, although they weren't prepared for certain scenarios like Billy Elliot winning Best Musical, but Elton John losing Best Original Score, and thus were tweaking the lyrics right up until the song went on. Neil Patrick Harris, being Crazy Awesome, pulled it off with aplomb, even throwing in an odd little bit of Painting the Fourth Wall halfway through ("Credits? That's not gonna stop me!").
Moved the following to Improv:
I put it here because it's pretty funny. 8p