Lisa is sent home from school with a note exempting her from games because she is sad,though she perks up when she meets fellow saxophonist Bleeding Gums Murphy and Marge encourages her to express her moods. Homer,meanwhile,sick of always beaten by his son at video games,finds a boy who can teach him to win but,just as he is about to triumph,Marge unplugs the television leaving Bart's victories unchallenged.
Lisa is sad and depressed. Marge is trying to figure out why she is so upset and what's troubling her. Meanwhile, Homer is trying to beat Bart at a game and can't win. Lisa eventually leaves the house and finds a jazz player on a bridge named Bleeding Gums Murphy and soon get along. When Marge finds Lisa, she tells her to act in her best mood, and Lisa becomes happier than ever.
A depressed Lisa's spirit is lifted when she meets a jazz-man, Bleeding Gums Murphy.
- Lisa's mood one school morning is rather dour, but noone seems to pay attention. Her attempts to be emotional in a saxophone solo in band are shouted down by Mr Largo, before Lisa finally refuses to play dodgeball, claiming she's too sad.
Marge tries to cheer Lisa up, but Lisa's dour mood continues, until one evening, she hears a saxophone being played. She follows it and meets Bleeding Gums Murphy. The two discuss about the blues and emotions, before Marge finds Lisa and brings her home.
Going to school, Marge recommends that Lisa smile, and this will help her regardless of her disposition. Lisa takes Marge's advice, but upon watching Lisa from afar and seeing her unhappy, Marge quickly takes Lisa aside. Apologizing, Marge says that Lisa should not hide her emotions, and that her family will be there for her. This manages to help turn around Lisa's mood, and she smiles for real.
Lisa then recommends the family attend a jazz club, where Bleeding Gums Murphy plays.