Another Oz clue from my 2009 Jeopardy! desk calendar. Today's clue, in the category Musical Theatre, reads:
In the Act I showstopper of this
musical, the song "Defying Gravity,"
the heroine declares she'll evade
those who would "bring her down"
Turn the page over, and you find that the correct response is, of course, "What is Wicked?"