This episode is nothing new in terms of sitcom tropes. A lot of tv shows in the 70's and 80's came to a point where the writers are out of ideas for the week, or the actors come from a stage or music background and they want to show their talents. Or they want to have a "fun, feel good" episode where they put their characters in unordinary situations to spice things up. If it isn't a fantasy scenario, the kids usually form a band--something for the audience to say, "Hey, I didn't know they could do that!" In this case they do a talent show--again. Makes the public relations team's job easier in entertainment show interviews. Hey, if you like the idea of seeing your favorite characters play dress up for the week and put on a show, enjoy. It's lazy storytelling, but I'm sure it made the cast and crew happy for a week. So be it.