Dude, We're Gettin' the Band Back Together! (Part 1 & 2) - S1-E22
Continuity mistake: During the song at the end, there is a zoomed out shot of the entire crowd. You can see Phineas and Candace both screaming with their hands in the air, their eyes closed, and Phineas is not holding a camera. When the camera instantly cuts to a close up of them, both of them have their mouths closed, their hands down, their eyes open, and Phineas is holding a camera.
Answer: "One boring day, Phineas recognizes an important truth; Summer vacation will end, and the teachers will want to know what they did on their summer vacation. And with these two kids, it has to be something extravagant..."http://uk.imdb.com/title/tt0852863/.
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