Jon Arbuckle finds an old accordion and takes up playing it, which Garfield cannot stand. Garfield does his best to try and get rid of it.
Garfield and Squeak are watching TV when Jon enters the house with an accordion. Garfield prepares to run out of the house. He becomes shocked at the sound of Jon's accordion playing. Squeak is likewise repulsed by the sound. Garfield explains to Squeak that the accordion is the second most hated musical instrument in the world, following bagpipes. Garfield and Squeak find Odie dancing to Jon playing the accordion in the shed. Squeak lures Jon and Odie into the house while Garfield grabs the accordion and throws it in the garbage.
As the garbage truck men arrive to pick up the garbage, Percy notices the accordion. He takes it out and starts playing with it while the other garbageman tells him to hurry up. Jon returns to the shed for his accordion, only to notice it missing. The latter garbageman returns the accordion to Jon, referring to it as "hazardous material."
Garfield and Squeak, proud of getting rid of the accordion, are about to take a nap when Jon comes in to "serenade [them] to sleep." Garfield jumps out of bed and lands on the floor. When Jon goes to get a first-aid kit, Garfield dashes out of the house with the accordion. He throws it into a lake, only for a man to point out a sign reading that throwing toxic waste and accordions into the water is forbidden. Meanwhile, Odie is following Garfield, sniffing for the accordion.
Garfield runs into an alley, wraps the accordion in a present, and gives it to a homeless man. He walks away, only for the man to deny the present and give the accordion back. Garfield then runs into a construction site and buries the accordion under concrete, with Odie still investigating.
Back at the house, Jon is worried about where Odie has gone. Odie, having dug the accordion back up, brings it back to his house. Garfield, hearing the accordion as Odie carries it, is convinced that he is having a bad dream about what he did. He rushes into the kitchen, where he runs into the accordion, outstretched as Odie tries to bring it inside. He gets injured after ricocheting from the accordion. Jon enters and is glad to find both Odie and his accordion, then takes Garfield to the vet.
Garfield is bandaged and in bed, and Squeak tells him that the accordion is broken now. Garfield is happy about this until Jon informs him that he got a new instrument: bagpipes. Garfield screams for it to stop, saying that he would rather have the accordion back.