As Bart and Homer watch television, Lisa practices the saxophone upstairs. But the ensuing din is so loud that Homer is unable to hear the program over the music. He sends Bart upstairs to make Lisa stop playing. Bart and his sister begin arguing, and during the ensuing struggle, Lisa’s sax flies out the window and lands in the street where it is crushed by traffic. Crestfallen, Lisa mourns the loss of her favorite instrument. This prompts Homer to recount the story of how Lisa got her sax. The year was 1990, and five-year-old Bart was beginning his very first day at school. But his first taste of kindergarten left Bart feeling depressed.

Homer resumes the tale, explaining how Bart’s behavior eventually became too disturbing to ignore. Dr. Hibbert diagnosed Bart as suffering from severe emotional dysfunction. Homer and Marge turned to the school psychologist, Dr. Pryor, for advice. During the meeting, Pryor’s attention turned to Lisa. He recognized how truly gifted Lisa was, and he encouraged her parents to nurture that special gift.

Marge picks up the story, recounting how the summer of 1990 brought with it a terrible heat wave. Despite a lack of money, Marge did not give up hope for finding some way of encouraging Lisa. She suggested to Homer that the 200 dollars they had been saving to purchase a new air conditioner be spent instead on something for Lisa. At first, Homer balked at the idea. But he promised Marge he would not spend the money until they had figured out a way to help their daughter. Meanwhile, back at school, Bart realized that his true calling in life was making people laugh. Then, one evening, Homer and Lisa happened upon a store window display containing an air conditioner. As Homer gazed longingly at a 200 dollar air conditioner, Lisa’s attention was drawn to a saxophone sitting in the window of a music store. Homer purchased the sax for his daughter. Back in the present day, Springfield is once again hit by a sweltering heat wave. But instead of buying an air conditioner, Homer purchases a replacement sax for Lisa.