Some 1,000 fans won a special opportunity to be part of the celebrations at Disney's El Capitan cinema on Saturday.

Many waited from 5am to be the first in to see the new sing-a-long version of High School Musical and High School Musical 2 and catch a sneak peek of the third new movie.

Inside, fans weren't disappointed. After the two movies played, Zac and the rest of the cast surprised crowds by taking to the stage to thank their supporters for the musical's success.

Speaking beforehand, Zac explained: "You know it's always great to get out and meet your fans and we just wanted to give them a little something extra."

Director Kenny Ortega added: "I left the editing room to come down here. I'm finishing High School Musical 3 but I couldn't miss an opportunity to say thank you."

Actress Ashley Tisdale said the franchise owes everything to its supporters: "Our movie was really for the Disney Channel. We never expected it to be so huge - it's because of the fans that it is such a phenomenon, so it's always great to see them face to face."