Scooby Doo! Stage Fright

ScoobyDoo Stage Fright is the twentieth film in the directtovideo series of ScoobyDoo films. It was released on August 20, 2013 by Warner Premiere.

Not long after checking in for the talent show, the Phantom appears in the opera house and Fred, Daphne and Velma attempt to catch him using the surveillance cameras, but are unsuccessful due to the Phantoms ability to seemingly appear in multiple places at once. While being chased briefly by the Phantom, Shaggy and Scooby notice the Phantom had a strange lemon scent and afterwards, the gang split up to search for clues. Fred and Daphne meet the owner of the opera house, Mel Richmond. They learn from Richmond that a Phantom once terrorized the opera house thirtyfive years ago when it was a disco.The dress rehearsal commences the next day. Fred and Daphne meet Emmas parents, who are hoping to get the prize money to save their home from bankruptcy. During the dress rehearsal, the Phantom sabotages most of the finalists acts, leaving Christine, Emma, and Fred and Daphne as the only contestants left. Due to these attacks, Fred and Daphne decide to use themselves as bait to lure the Phantom out. The gang manage to track down a Phantom, only to find it is the original Phantom from the 70s, a man named Steve Trilby. Steve admits to the gang that he vandalized the opera house during the 70s, due to his hatred over disco music, but that now he only goes into the opera house to get food. The gang return to the stage to find the Phantom setting fire to the opera house. With the help of Steve, they catch the Phantom, who is revealed to be Mel Richmond. However, the gang learn that Richmond isnt the Phantom they are after when they hear the Phantom threatening to destroy the place unless Christine wins. ........

Source: Wikipedia