'High School Musical' star Vanessa Hudgens is starring in a different kind of big-screen musical, a movie called 'Rock On.' and ET is first on the set of the teenage romance to chat with the bombshell brunette.

"My look is definitely a little bit darker than in 'High School Musical,'" Vanessa tells us. "I kind of play the 'emo girl.' She wears a lot of black and she always has long sleeves with thumbs in them."

Vanessa plays Sam -- the "five" is silent -- a teenage rocker misfit caught up in her high-school's all-important battle of the bands! The movie, which just started shooting, features newcomer Gaelen Connell as Will, her talented but shy ally, "Friday Night Lights"' Scott Porter as a rival singing frontman, Lisa Kudrow ("Friends") as Will's mom and "Phil of the Future" star Alyson Michalka.