"As a performer and a musician, you like to think that you're always pushing yourself," she says. "In this show, a lot of the music is a lot more vocally demanding, so you're really giving your heart and soul out there. It's actually a great feeling to know that you're pushing yourself every night and getting such a great reaction from it."

That constant touring has had an interesting effect on Agnew: While she is in some ways still an ordinary teenager, her life experiences have left her light years beyond others her age.

"I remember going home and doing geography class and being able to tell my peers all about the rest of the world - places you could never dream of seeing before you're 20," she says.

And, any other 19-year-old who wants to complain about a busy schedule needs only look to Agnew for perspective. Though she is done with school, Agnew is teaching herself Italian and taking an online child psychology class while touring the world.

"The show is the best two hours of the day," she says. "The minute you get onstage, there's this energy that comes from somewhere, you don't know, it just comes out of midair. It kind of grasps you and takes you with it. It's always such a buzz."