The show, which follows a group of cheerleaders, was picked up by The CW earlier this month.
Tisdale explained that her role as the head cheerleader Savannah is completely different from her High School Musical character Sharpay.
"[Savannah's] not a mean girl," she told Zap2It. "She's not a mean girl. But she's also not like the girl... I play Maddie on The Suite Life [of Zack & Cody] - she's kind of the sarcastic, down-to-earth girl, working girl and Sharpay was the mean girl.
"You think Savannah's going to be mean, but she really actually isn't. She means well, she's just a little bit off... She's definitely off. I mean, she's the captain of the cheerleaders. She's a flyer up on the top of the pyramid. You have to be a little bit off to do that."
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