Sabrina: The Animated Series 1x14

Greendale throws a talent show and everyone enters it. Sabrina, Aunt Zelda, Aunt Hilda, and Chloe decide to form a rock group called the Flavor Babes, but they are bad and they lose the competition to Gem. After failure they all decide to use a spell to make them better and famous like pop stars. It works but they end up being snobs and seperating the group!