Lisa sings to the rest of the family to sleep with a rendition of "Mockingbird" (after they are all suffering from the system shock of an all-vegetable meal), which is so good that she decides to enter Krusty's "Li'l Starmaker" competition (with a grand prize of being animated into an Itchy & Scratchy cartoon). However, when another singer (voiced by American Idol's third winner, Fantasia Barrino) sings a much better version of "Mockingbird", Homer quickly pens a song about Springfield which is a hit with the crowd, and Lisa qualifies for the show. With Homer's help (especially in handling with stagehands), Lisa makes it to the finals, but when Homer goes one step too far with his stage fathering, she fires him, and he ends up lending his talents to her final competition.
Aside from Lisa, everyone in the family contracts food poisoning after eating organic produce from The Farmers’ Market. After nursing the family back to health, they persuade Lisa to participate in a Krusty sponsored “Li’l Starmaker ” competition, with the first prize winner being animated into an Itchy and Scratchy episode. Lisa panics during the competition when a girl named Clarissa Wellington performs a better rendition of “Mocking Bird” and Homer saves the day by hammering out a manipulative tune about Springfield that leads Lisa to victory. With a win under his belt, Homer becomes a stereotypical star-crazed parent and manager who ultimately drives Lisa to fire him. A distraught Homer reacts by taking Lisa’s rival, Cameron, under his wing and starts grooming him for the finals. Lisa comes to realize that her relationship with Homer is more important than the competition and performs an apologetic song. Homer reunites with his daughter before Cameron performs an egotistical song Homer prepared to sabotage the young boy’s performance. Lisa is grateful that Homer sabotaged Cameron's performance for her. Homer states "I'll always be there, not even DEATH will stop me" while hugging Lisa.