It's important to let each artist do what makes him or her feel comfortable. Success should be a by-product of that.
When you audition for things, there's pressure to go in there with a complete performance, and it's kind of unfair because, if you get it, you'll have rehearsal and talk about it, and you'll have plenty of time with the script. So, for me, I really do feel like an audition is a sketch of what you might do.