- Squidward Tentacles
- SpongeBob SquarePants
- Eugene H. Krabs
- Frankie Billy
- Nancy Suzy Fish
- Jennifer Millie
- Baby Rechid
- Betsy Krabs (heard only)
- Corporal Sterling (debut)
- Norma Rechid
- Abigail Marge
- Harold Bill Reginald Scott
- King Neptune (mentioned)
- Keeper of the Horned Forest (debut)
- Alternate-Universe Squidward
- Giant Patrick (debut)
- Pressure (debut)
- Clarinet Auditions Judge
Squidward arrives at the Krusty Krab as happy as ever because of his upcoming clarinet recital. He is repeatedly getting pummeled, such as Thaddeus' morning breath in his face, or getting the door slammed on him, but since his clarinet is safe in a suitcase, he is happy. But when Nazz Rechid comes to the Krusty Krab, and her new baby drools on the clarinet, Squidward bursts with anger. He demands Mr. Krabs to give him a place to store his stuff, and Mr. Krabs gives him his Navy locker, and SpongeBob single-handedly cleans it.
He stores his toothbrush, while Squidward puts his clarinet in there, not risking it getting soiled before his presentation. While Squidward is going through his daily routines, he discovers SpongeBob is always doing something to the locker. In fear for his clarinet, he goes to see what happens, and leaves loose change on the floor when he was giving it to the customer. Just then, Mr. Krabs jumps out wildly and acts like a gorilla, scaring everyone away from the loose change he hears.When Squidward crawls inside the locker, it is revealed SpongeBob had converted it to a whole room, and the second time he visits it, he finds his clarinet gone, and goes looking. He discovers a small door near the floor, and crawls through it, only to enter a mysterious forest, made of clarinets. He spots his, just before he is picked up by a large eagle, "The Keeper" of The Horned Forest or Clarinetland, who tells him to learn respect, and to grant peace to clarinets, and that a clarinet cannot be owned. In desperation, he claims he has learned respect and tries to escape, but the eagle, "The Keeper" does not believe him and swallows him.
Squidward then finds himself chasing SpongeBob for his clarinet, into a giant pinball machine, where Patrick in giant size finds Squidward as a prize. Patrick later says it is THE PRESSURE (a giant vacuum cleaner) that is doing all of this. Suddenly the vacuum explode and Squidward finding himself chasing SpongeBob, literally through space, finally grab him, returning in the locker. Mr. Krab and SpongeBob return to the kitchen and Squidward realizes that it was just a dream. SpongeBob reveals to Squidward that he had the clarinet for the whole time, after seeing Squidward upset. Before Squidward go to the presentation, he locks SpongeBob into the locker. However, in the presentation, he finds SpongeBob in his case, and runs from the stage, right before he gave the presentation, revealing he was giving him the clarinet.
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
• Happy Sponge Chase Vibes - Nicolas Carr [title card]
‣ Honolulu March - Hans Haider [opening]
• Salty Krab Jig - Michael Bolger, Nicolas Carr [Squidward's happy]
• Steel Licks 22 - Jeremy Wakefield [baby drools on Squidward's clarinet]
‣ Shock (f) - Dave Hewson ["I can't take this anymore!"]
• Daily Chores Jig - Michael Bolger, Nicolas Carr [Squidward demands a place to put his stuff]
‣ The Tip Top Polka/The Cliff Polka - Chelmsford Folk Band [SpongeBob cooking Krabby Patties]
‣ Dirgey - Nicolas Carr, Steve Marston [Krabs' old Navy locker]
‣ Noodly Shenanigans - Nicolas Carr, Barry Anthony [Krabs says Squidward will have to share the locker]
• Earl's Revenge - Sage Guyton, Jeremy Wakefield [SpongeBob cleaning the locker]
‣ Lap Steel - Nicolas Carr ["Order up, SpongeBob!"]
‣ Vibe Q Sting - Nicolas Carr ["SpongeBob, what do you think you're doing?"]
‣ The Tip Top Polka/The Cliff Polka - Chelmsford Folk Band [velvet-lined locker]
‣ Harp Ding - Nicolas Carr ["Loose change!"]
‣ Terror - Alan Braden [Krabs yells at customers]
‣ Silly Shenanigans - Nicolas Carr, Barry Anthony [file cabinets inside the locker]
• In a Minor Mood Jig - Michael Bolger, Nicolas Carr [SpongeBob working on the locker some more]
• Tension Bits - Nicolas Carr, Sage Guyton, Jeremy Wakefield ["My clarinet!"]
‣ Unknown Track 57 - Squidward looking for his clarinet
‣ ? [Squidward arrives at Clarinetland]
‣ ? [Eagle eats Squidward]
‣ Unknown Track 57 - Squidward sees SpongeBob laughing
‣ Graveyard - Johnny Pearson ["Stand still, you idiot!"]
‣ ? [Squidward falls into a strange room]
‣ Shock - Cornelus Joh Bolten ["What the... SpongeBob? SpongeBob?!"]
‣ Big Top Marching Band - [Optigan sample] [Squidward's mirror reflection swallows a clarinet]
‣ Unknown Track 109 - Nicolas Carr, Barry Anthony [Squidward chases SpongeBob on a clarinet]
‣ Unknown Track 90 - "Hey, what are you doing here?"
‣ Blue Danube Waltz - Johann Strauss I [SpongeBob and Squidward floating in space]
‣ Hawaiian Cocktail - Richard Myhill [Squidward melts]
• Salty Krab Jig - Michael Bolger, Nicolas Carr ["I just sweet-talked an old lady out of 20 bucks for a Krabby Patty!"]
‣ Hawaiian Cocktail - Richard Myhill ["Squidward, are you okay?"]
‣ Unknown Track 45 - Nicolas Carr [SpongeBob takes out Squidward's clarinet]
• Slide Whistle Stooges - Nicolas Carr, Sage Guyton, Jeremy Wakefield [Squidward puts SpongeBob in the locker]
‣ Lap Steel - Nicolas Carr [clarinet audition]
• 12th Street Rag 3 with Bass - Nicolas Carr, Sage Guyton, Jeremy Wakefield [ending]
- This episode is available on the Complete Seventh Season, Sweet & Sour Squidward, and Next 100 Episodes DVDs.
- Although this episode premiered in 2010, it was made in 2009 according to the credits.
- When Squidward opens the drawer after SpongeBob expands the second time, the case can be seen inside, but it then reveals the drawer to be empty with the exception of the note.
- This is the second appearance of the Alternate-Universe Squidward following "The Algae's Always Greener." In this episode, he is the reflection of Squidward in the mirrors.
- This is the third episode in which the majority is revealed to be just a dream. The first is "Procrastination" and the second is "Doing Time."
- Despite the title of the episode, Squidward remains in Clarinetland for a minimum of one minute.
- Squidward's line, 'You tell me, what in the Wide World of Sports is this place?', references a similar line made in the Mel Brooks film Blazing Saddles, which itself references the old Wide World of Sports anthology series that aired on American Broadcasting Company.
- Squidward and SpongeBob tumbling through space to classical music is a reference to Stanley Kubrick's 2001: A Space Odyssey.
- The fact that Squidward finds another area in the locker is similar to that of the Chronicles of Narnia book series.
- The title as well as the plot, is a reference to the 1865 book and the subsequent 1951 movie Alice in Wonderland.
- When Squidward tries to slam SpongeBob, the latter escapes from the former's grip, then he laughs upside-down in a hole before it vanishes.
- When SpongeBob touches the dirty locker, spiders eat his arm and reveals bones, despite him being an invertebrate.
- SpongeBob places his old and filthy toothbrush inside the locker next to Squidward's clarinet. However, later on, the toothbrush disappears and isn't seen for the rest of the episode.
- When Squidward hands a book of "Bikini Bottom Labor Regulations," Mr. Krabs grows hives, claiming he is allergic to it, but in the next scene where Mr. Krabs holds the same book, he isn't affected at all.
- In the beginning the Gallery Grub is black chalkboard.
- The suitcase is blue, however, at the end, it is purple.
- When Squidward crawls through the hole, the note is gone.
- When Thaddeus' breath punches Squidward in the face, his hat falls off, but when he gets back up, it's on his head again.
- When SpongeBob with load of appliances walks past Squidward while he is giving change, the Galley Grub is misspelled as "Gally Grub."
- Before Squidward opens the curtain to Clarinetland, he has his work hat on. After he opens the curtain, his work hat is gone for the rest of the episode.
- When the alternate universe Squidwards blow music at Squidward, he stands up briefly screaming. At this moment, he only has two legs instead of four.