Even if you're improvising, the fact that beforehand you know certain things will work helps you make those improvisations successful. It really helps to have a certain amount of knowledge about musical structure.
“We're all grown women now; if we wanna do something, we can't be stopped!”
“It's a wonderful thing working with young actors. I know a lot of people don't like working with children. I actually adore it, because you watch their imagination open up and you watch them start to learn this job that I've been doing for so long. They come with such a lack of cynicism.”