Continuity mistake: Before "Gotta Go My Own Way" in the kitchen scene, the bracelet on Gabriella's wrist is on her right wrist, but when she goes out to confront Sharpay, her bracelet is now on her left wrist. It stays on her left wrist until she gets to the lockers, then her bracelet is back on the right wrist and stays that way throughout the rest of the song. (01:13:50 - 01:19:55)
Continuity mistake: Before the school bell rings, Jason asks Ms. Darbus for her favorite summer memory. When everyone turns to look at him in the shot from the front of the class, there is a book under Troy's desk, which is not there in the previous or following shots. (00:01:25)
Continuity mistake: Just as they start to sing "What Time Is It" the top of Troy's boxers are visible above his belt. He starts out wearing light colored boxers, which change to dark, then light, and again to dark colored boxers during this song. (00:02:05)
Continuity mistake: Both Jason and Chad, who are wearing blue shirts and white aprons, are serving burgers, when Troy tells Chad that he wants Swiss cheese on his burger. Next shot in the kitchen, when Chad hands that burger to Zeke to add the Swiss, behind him Jason has been on kitchen dish duty wearing the green tee and blue apron. He can't be in two places at once. (00:57:55)
Revealing mistake: When Troy crouches down on the rocks, and leans down to see his reflection in the water, oddly the reflection is not reversed, yet his hair is combed the opposite way. (Did the director actually think that if Troy's hair was combed the opposite way it would pass as a reversed reflection?) Additionally, when he crouches down, the bottom button on Troy's shirt is unbuttoned, but in the reflection (as well as in the previous and following shots) the bottom button is buttoned up.
Continuity mistake: During "Work This Out" in the close-up when Troy sings, "A way to have fun," his name tag disappears, then reappears.
Continuity mistake: At the start, when the camera pans through the doorway, as Ms. Darbus speaks on the 'stage', there is nothing between Zeke and the doorway. In the next shot, a tall wood stool appears out of nowhere right beside Zeke. Also, the height and structure of the stool he is sitting on changes.
Continuity mistake: At the end of "Work This Out" the group take to the center of the kitchen floor for the final dance routine. To the left, the long white apron string either hangs down or lies on the table over and over again. (00:23:55)
Continuity mistake: At the start, when the camera pans through the doorway of Ms. Darbus's classroom, Zeke sits on a tall stool that is about 3 feet high. Oddly enough, in the following shots, the munchkin stool he now sits on only reaches the height of about 1 foot. (Did they really think we wouldn't notice?) The wood stool also moves forward a few feet. (00:00:50)
Continuity mistake: At the U of A basketball court, in the overhead shot Troy sits down beside a crumpled white towel, which disappears in his close-up as he calls Gabriella's cell. That towel returns in the subsequent overhead shot, when he continues to play basketball. (01:08:40)
Continuity mistake: The binoculars in Ryan's right hand disappears and reappears after the sprinklers have been turned on, when he and Sharpay spy on Gabriella and Troy. (00:27:15)
Continuity mistake: After Fulton gives the group their staff assignments in the kitchen, during "Work This Out" there are table order tickets hanging over the grill and fry stations. In some consecutive shots the amount goes from three to one, to three, to one, back to three, etc. (00:22:50)
Continuity mistake: As Gabriella and Troy dance out of Ms. Darbus's classroom, there are two books (yearbook and schoolbook) on Taylor's desk (in front of Jason). Next shot, when Ms. Darbus slams schoolbooks onto Jason's desk, there is only one book on Taylor's desk. (00:02:40)
Continuity mistake: After winning the Star Dazzle award, Ryan hugs Sharpay with the trophy in his hand. Part of the star at the top breaks off (watch Kelsi's face as it flies past her), as the rest of the star on the trophy bends down. In the next shot the star is intact. (01:43:05)
Continuity mistake: During "Work This Out" after Troy and Gabriella put away their spoons in buckets, the next shot Troy has a set in his right hand which he places on the table. (00:23:30)
Audio problem: When Troy and Gabriella are singing "Everyday," Troy sings with his microphone away from his mouth numerous times during the scene, yet he is still heard just as well, and not at a lower level, like he should be. (Within the context of the film, this is sung live on stage and is not implied to be pre-recorded.)
Continuity mistake: During "All For One" at the pool party, mid-song the six singers split up into two groups of three - two girls and a boy and two boys and a girl; Sharpay, Troy and Chad walking down to their right (viewer's left) and Ryan, Gabriella and Taylor walking down to their left (viewer's right). Next shot, still singing and walking down, the three girls are walking to their left and the three boys are walking to their right. (01:46:20)
Visible crew/equipment: Throughout the film, set equipment such as the boom mic and pole, reflector screen or monitor are visible in the reflections of characters' eyeglasses and sunglasses. Such as when one of the Sharpettes asks, "So what's the theme of the summer's talent show?" in Sharpay's next close-up the boom mic and pole are visible in the reflection of her sunglasses.
Visible crew/equipment: During Fabulous in the beginning of the song if you look into Sharpay's sunglasses you can see a white light reflector.
Continuity mistake: In the Lava Springs kitchen, Kelsi holds up a dish towel, when they sing, "Maybe there's a better way to fix this greasy mess," and she drops the towel. The towel repeatedly moves around from the cart's bottom shelf, to the floor and disappears repeatedly throughout the scene. (00:22:25)
Answer: It's a Musical. Instruments that aren't shown are always playing like this in these types of movies.