Season 6, Episode 22
Bart swallows a metal object hidden inside one of Krusty the Klown's breakfast cereals and has to undergo an operation to remove it. Whilst at the hospital Lisa hooks up with old pal Bleeding Gums Murphy, who after performing a duet with her, gives her his saxophone as a gift shortly before he passes away.
There are references to The Lion King and The Empire Strikes Back.
See here for more details.
Notes & Screenshots: Lord Heath