Vanessa Hudgens, Gaelan Connell, Alyson Michalka, Scott Porter, Lisa Kudrow. and other stars rocked Hollywood at the premiere of the new film, 'Bandslam!'

Vanessa Hudgens tells ET about learning to play a new instrument for the film, and explains that although she did not have the normal high school experience she still ended up with a few nicknames.

"I learned to play the guitar for this," she says. "I never actually went to high school but my mom calls me Van and my friends call me V. Nothing too embarrassing thankfully."

Alyson Michalka, of the hit music duo Aly & AJ, opens up to ET about her role in the film and explains that the cast members became very close while filming.

"It was nice to be able to step aside and not be a songwriter," she says. "We've all become really close friends. Everybody keeps in contact. Me and Vanessa are like best friends -- it's a very genuinely, honest cast."

Scott Porter tells ET about playing the bully in the film, and about his real-life music experience.

"It was a good time, I was never big enough to do it in real life -- so bullying Gaelan in the movie was a good time," he says. "I was a professional beat boxer for seven years, but I do actually play the guitar now. I learned for the movie and continue to play now. Everybody in the movie had to play live. Everybody had to be able to perform their songs, which is why the casting was so intense."

In the new film, aspiring musician Will Burton (Connell), starts up a rock band after moving to a new school. The new band sets their sites on the coveted prize of the school's "Bandslam" competition but must take on the favored band the Glory Dogs.

Watch the video for more with the rockin' stars -- plus, 'New Moon' star Kiowa Gordon tells ET about being cast as a member of the wolf pack, and spills secrets about the 'Twilight' sequel!

'Bandslam' turns up the volume in theaters August 14, but for more movie news and exclusives, check out ETonline's Summer Movie Guide!