We start off with Bart eating breakfast with the family. Marge starts quizzing him on the test he'll be taking that day, but it's obvious Bart isn't prepared. Just then, Bart takes a bite of Krusty-O's cereal and swallows a jagged metal O (hey there's one in every box!). This makes Bart sick of course, but he goes off to school anyway.
Krabappel won't let him go to the nurse so Bart takes the test. Afterwards he's finally allowed to go where he finds Lunchlady Doris working as the nurse. Bart ends up unconscious on the floor and is taken to the hospital where he has his appendix removed.
While the Simpson family is visiting Bart, Lisa finds her old jazz hero, Bleeding Gums Murphy, in a hospital bed as well. They visit for awhile and Bart shows up baring his butt, clearly on the mend.
Later, Lisa has a recital and returns to tell Murphy about it, but finds he has passed away. Meanwhile, Bart earns $500 from a lawsuit due to the cereal incident. Seeing Lisa sad, he uses the money to buy Murphy's album which Lisa takes to the local jazz station to have it played as a tribute.
At first the radio signal is weak, but Murphy shows up in a cloud, a-la The Lion King, and makes the signal carry across the city so everyone can enjoy it. Before leaving, Murphy and Lisa jam.