Fluttershy, while walking with Angel Bunny in the forest, hears what seems like the calls of an animal in pain and races to find it. Instead, she finds Pinkie Pie playing a musical instrument called the yovidaphone, which she got from Yakyakistan. Pinkie says she's only just learning how to play, explaining its dissonant sound.
Later, Pinkie starts practicing in town, upsetting the residents. The Mane Six, seeing how attached Pinkie is to the instrument, agree to let Pinkie be, given she is only learning the instrument and should get better. However, after a few days, Pinkie's yovidaphone playing is as bad as when she started, and has gotten in the way of everypony's regular routines: Rarity's fall line has become a mess, Rainbow Dash got distracted during a Wonderbolt race and ended up in second place, Fluttershy and her animals have lost sleep, and Applejack's entire apple crop has been turned into mush. Recognizing that they should really tell Pinkie she's not getting better rather than pretend she is, the others explain to Pinkie how her playing is annoying the rest of town. Pinkie pauses and seems to agree, dumping the yovidaphone in the street, seemingly ending the problem. However, Pinkie cries to herself as she watches the yovidaphone be taken out with the trash that night.
When the Mane Six next see Pinkie, they see that she's lost all her emotions. Knowing that Pinkie had loved playing the yovidaphone, they try to engage her in activities that she also loved to do, but cannot break her out of her depression. When they go to visit her a few days later, they discover Maud Pie is packing up all of Pinkie's belongings, as she is moving back to the rock farm. Maud also tells them that Pinkie went to Yakyakistan to spend a few days there.
The Mane Six travel to the yaks and discover Pinkie wallowing in her depression with ice cream, while listening to a yak playing a yovidaphone with great skill, making the instrument sound pleasant to hear. They try to coax Pinkie to come back to Ponyville, but she's further depressed that she would never be as good as the yaks on playing the yovidaphone. This gives the Mane Six an idea, and they convince Pinkie to take the stage and show the assembled yaks how she plays, hoping this would help break Pinkie's mood. Despite knowing the yaks' temperament, Pinkie agrees to try it, and as she plays, still as discordant as before, she regains her normal happy self. To the ponies' surprise, the yaks applaud Pinkie's performance, as they tell her that it is not so much the music that the yovidaphone makes that makes it great, but how it brings joy to those that play it. The Mane Six are relieved to have their Pinkie back, while she, pleased as punch, continues to play on.
- An Aesop:
- Even if a friend is not good at a hobby, always be supportive as to not hurt their self-esteem.
- It's okay to enjoy something even if you're not very good at it.
- Big Eater: Pinkie has managed to knock back 25 sundaes by the time her friends find her in Yakyakistan.
- Brick Joke: The bird who lost its feathers thanks to Pinkie's yovidaphone playing later appears during the picnic Fluttershy uses to try and cheer Pinkie up (wearing a sweater over its still-featherless body).
- Brutal Honesty: The others regret having to tell Pinkie that she isn't good at the yovidaphone.
- Color Failure: In addition to her mane and tail becoming straight, Pinkies colors become washed out and disaturated when she becomes depressed.
- Comically Missing the Point: While trying to tell Pinkie Pie that she stinks at the yovidaphone, Rainbow Dash brings up the aforementioned incident with Celestia's acting. Pinkie Pie, however, doesn't get the comparison.
- Continuity Nod:
- The episode is titled after a tune that inspired the chase scene pastiche featured in a couple first season episodes.
- When Fluttershy hears Pinkie's yovidaphone playing during the Cold Open, she initially believes to be either "a herd of injured chimerae" Or "Cerberus with snifflitis in two of its heads and kennel cough in its third".
- Pinkie wears her "honorary yak" helmet while playing the Yovidaphone.
- Pinkie Pie once again decides it's better to pretend she's happy rather than let her friends know that she's being bothered by something. She seems to have gotten better at faking it, though.
- Covered in Gunge: Applejack and her family end up covered in applesauce after Pinkie passes by the family orchard.
- Death Glare: When Pinkie Pie disturbs the Wonderbolt race with her yovidaphone, Moonlight Raven is seen glaring at her as she covers her ears like the rest of the crowd.
- Deliberately Monochrome: As Pinkie becomes more and more depressed, her colors fade to the point that she is completely gray by the end of the Failure Montage and the trip to Yakyakistan.
- Dreadful Musician: Pinkie Pie and the yovidaphone just don't mix. Her playing is so bad, it causes a bird flying overhead to lose all its feathers, and the apples in Sweet Apple Acres to explode into applesauce.
- Drowning My Sorrows: Pinkie does this with ice cream sundaes when she arrives in Yakyakistan. Also doubles as Getting Crap Past the Radar.
- Everyone Has Standards: Inverted by the Yaks that Pinkie eventually performs for. They normally have incredibly high standards for anything from their culture and will fly into a rage at anything short of a 100% perfect recreation. However, when Pinkie badly plays the yovidaphone for them, they still cheer for her despite it sounding nothing like the Yak that played it earlier. Apparently, as long as the creature playing the yovidaphone is happy, they consider the resulting music to be perfect.
- Everything's Louder with Bagpipes: The yovidaphone is the Equestrian equivalent of bagpipes, and can sound just as annoying.
- Expository Hairstyle Change: After her friends tell her to stop playing the yovidaphone, Pinkie's mane and tail lose their usual poofiness and look completely straightened-out.
- Failure Montage: The rest of the Mane Six attempt to cheer up Pinkie through a variety of activities, only to fail miserably.
- Forgot About His Powers: The loud noise is bothering everyone but if Pinkie Pie can't even play the instrument, she falls into a depression. It's not like there's a way to simply soundproof the area around her...
- Furry Reminder: Fluttershy falls asleep standing up.
- Got Volunteered: The Mane Six (sans Pinkie) try passing the buck to the other members when trying to tell Pinkie the truth.
- Hypocrite: Applejack insists that Pinkie be told the honest truth about her yovidaphone playing. But when the Mane Five confront her, Applejack is unwilling to tell Pinkie herself, starting off the cycle of Got Volunteered by telling Pinkie Rarity has something to say to her.
- Idiosyncratic Wipes: The montage of Pinkie's friends trying to have her doing activities she likes use related things wiping the screen for transitions, like balloons rising, chocolate flowing, a balloon deflating, and cake batter flowing.
- I'll Tell You When I've Had Enough!: When the Yak tells Pinkie that she already ate 25 ice cream sundaes, she gives an equivalent of this, demanding another.
- Innocently Insensitive: Pinkie is utterly oblivious to how her yovidaphone playing is disrupting the lives of everypony in Ponyville (such as waking up all the animals in Fluttershy's nursery, or messing up Rarity's sewing).
- Logical Weakness: Fluttershy's Speaks Fluent Animal abilities don't work with Gummy, since Gummy isn't actually "speaking" (as in, making any sounds that could be translated) at all.
- Malaproper: Invoked when Applejack and Rarity discuss Pinkie's yovidaphone playing.Applejack: Anypony else think that sounded like an apple core cut up in a pulp grinder?
Rarity: Apple-solutely! Uh, absolutely.
- Mathematician's Answer: Maud answers the Mane Six's questions about Pinkie this way. While technically correct, the answers frustrate the girls.
- Reckless Gun Usage: Not surprisingly, ponies are not versed in basic gun safety. When Pinkie's Party Cannon misfires during the Failure Montage, Applejack looks down the barrel, whereupon it fires confetti into her face. She's lucky confetti is the worst ammo that that cannon holds.
- Running Gag: When Pinkie prepares to play the Yovidaphone, she tends to say "And a-one, and a-two, and a-I know what to do!"
- Second Place Is for Losers: Rainbow Dash complains that Pinkie's awful playing caused her to land second place in the flying competition.
- The yovidaphone is modeled after real-world bagpipes (though it has a mouthpiece like a brass instrument rather than a reed like a woodwind). Bagpipes are similarly not easy to learn and an unskilled player will very much sound like Pinkie when they first try it.
- The yak waitress's voice is an uncanny impression of June Foray as Nastasha Fatale or Magica De Spell.
- Stepford Smiler: When Pinkie is told she should stop playing the yovidaphone, she responds in her usual cheery manner. However, she breaks down in tears later that night.
- Teleportation: Twilight demonstrates that she can teleport four ponies alongside herself to make it a surprise for Pinkie Pie.
- Titled After the Song: Named after the song "Yakety Sax" by Boots Randolph, made famous by The Benny Hill Show.
- Translation by Volume: Spike tries asking Gummy where is Pinkie Pie by speaking louder and slower. He doesn't have any more success than the ponies, though.
- The Un-Smile: After making a mess out of baking cupcakes, Rainbow tries to get a smile out of Pinkie by rearranging her features manually. The result is... unnerving.
- Vertigo Effect: When Twilight drops the bombshell to Pinkie that they think she's not good at the yovidaphone and should give it up, there is a zoom on Pinkie Pie while the background is getting farther away.
- Walking Wasteland:
- Pinkie's yovidaphone-playing causes apples to explode into applesauce, while still on the tree.
- While depressed, Pinkie causes flowers to wither and balloons to deflate when she walks through the marketplace.
- We Are Not Going Through That Again: Said word-for-word by Applejack when she nixes Twilight's idea to find a spell to improve Pinkie's playing.
- What Happened to the Mouse?:
- The party that the others are planning for Pinkie Pie is forgotten when they learn she's left Ponyville.
- All the legitimate problems that the other Mane Six were having that were shown with Pinkie blaring her Yovidaphone. They never get brought up again or resolved after they accidentally hurt her feelings.
- Your Princess Is in Another Castle!: After the others inform Pinkie Pie that she's not good at playing the yovidaphone, it seems like the trouble is over, but since this is even before the second commercial break, it is obvious that there would be other problems.