Squidward, who is very tired, starts his night time routine. He drinks some warm milk, turns on his noise maker (which makes a bubbling sound), dims the lights, sings himself a lullaby: "Sleep, little Squidward, catch some winks. Everything and everyone clearly stinks," and attempts to sleep. He then gets quickly woken up by a giant, loud burp caused by SpongeBob and Patrick drinking a large amount of soda, which SpongeBob and Patrick both laugh at. Squidward tells SpongeBob to stop and that he hasn't slept for three days. He also tells him that he has to be ready for the Bikini Bottom Philharmonic auditions. SpongeBob tells Squidward to take a walk, and Squidward decides to follow his advice. He finishes his walk and goes to SpongeBob's pineapple, thinking that it's his moai. SpongeBob turns into a bed, and Patrick and Gary joins with Squidward sleeping on SpongeBob.
The next morning, the gang has woken up, with the exception of Squidward. SpongeBob and Patrick try to wake him up, but to no avail. The two later made Lab Squidward, but unfortunately crashes outside the lab and wreaks havoc to the town. Patrick later gets the idea of crawling up Squidward and playing him like a puppet. Later on, the two got ready to control Squidward's body. The two play around with Squidward's body for a while, then they both leave (while in Squidward's body) for the Philharmonic. While doing so, they have trampled on several people and crash a car. A police officer tells the two that the place is a "no-dancing zone".
SpongeBob realizes he doesn't know where the concert hall is. He later asks an old lady where the concert hall is. While doing so, they catch up the attention of several people. SpongeBob sees a bus that leads to the concert hall and boards it.
The two arrive at the concert hall for the audition, with Octavius Rex and the conductor inside it. While entering the concert hall, the two made a big mess on the stage. SpongeBob asks where Squidward's clarinet is, and Patrick says it was on his backside. The two has made Squidward play the clarinet, at first terrible and off-tune (which led to the conductor calling in the next person) but later plays it well, much to the surprise of the two. In the middle of the audition, Squidward wakes up, and is surprised to see he is at the audition. Squidward later finds out that the SpongeBob and Patrick were inside of him, and later spits them out of his body.
The conductor has later called Squidward a "musical genius", much to the happiness of Squidward. He later plays (without the two's control) and the two gets irritated by it. The screens cuts to the bus, with SpongeBob and Patrick sleeping beside Squidward. Squidward later sees Lab Squidward wreaking terror in the city while oddly playing a "clarinet" (in reality just a house), oddly much to the joy of the townsfolk.
This episode is set after 2012 because one woman in the background was talking on a smartphone, and smartphones are almost completely a common thing since after 2012.
This is the second episode in which a character notices characters literally inside their head, in this case Squidward saw SpongeBob and Patrick in his head. The first was "Plankton!," when SpongeBob notices Plankton inside his head.
This and "Krusty Katering" are the last episodes aired to use the 2009-2017 Nickelodeon Productions logo.
Apparently, Lab Squidward can make better clarinet sounds than actual Squidward.