A lot has changed since High School Musical debuted on Disney Channel Jan. 20, 2006. Head back to East High to find out what Zac Efron, Vanessa Hudgens, Ashley Tisdale and more stars are up to now.

Also joining the cast this season are Kylie Cantrall ... that Disney has decided to make the long-awaited "High School Musical 4: The Reunion" movie on location at their beloved high school.

Vanessa Hudgens reveals why she returned to High School Musical set in nostalgic Instagram photo Zac Efron returns to his High School Musical roots in mysterious new photo: 'Don't you forget about me' ...

This time, a whole new cast of students are attending ... The Series' been renewed for season 4? Per the show's Instagram, "High School Musical: The Musical: The Series" is confirmed for a fourth ...