Fact1: Former Canterlot High School bully Sunset Shimmer is ostracized by most of school despite efforts to atone for actions, Fact2: Fluttershy and Rarity have formed rock band called Rainbooms to participate in school 's upcoming musical showcase, Fact3: song turns other students aggressive and competitive convincing them to turn friendly showcase into Battle of Bands, Fact4: Sunset and friends are protected from song by own magic, Fact5: sirens from Equestria feed on negative emotions to fuel singing powers for goal of world conquest
Output: Former Canterlot High School bully Sunset Shimmer, who has reformed after being defeated by the magic of Twilight Sparkles crown, is ostracized by most of the school despite her efforts to atone for her actions. Her only friends are the counterparts of Rainbow Dash, Applejack, Pinkie Pie, Fluttershy and Rarity, who have formed a rock band called the Rainbooms to participate in the schools upcoming musical showcase. The five girls discover that the magic left over from Twilights crown has given them the ability to grow ponylike ears, tails, and wings whenever they play their instruments. Hoping to make a fresh impression, Sunset gives a school tour to three new students – Adagio Dazzle, Sonata Dusk, and Aria Blaze – and informs them of the showcase, unaware that they possess magical singing voices. Calling themselves the Dazzlings, the trio perform a song that turns the other students aggressive and competitive towards each other, convincing them to turn the friendly showcase into a Battle of the Bands. Sunset and her friends are protected from the song by their own magic, but fail to convince the bewitched Principal Celestia and Vice Principal Luna of the danger. Sunset remembers a book that magically copies whatever she writes in it to another kept by Princess Celestia, her mentor from the parallel world of Equestria, which she uses to send a message requesting Twilights help. Princess Celestias book is delivered to Twilights castle in Ponyville. Receiving Sunsets message, Twilight deduces that the Dazzlings are banished sirens from Equestria that feed on negative emotions to fuel their singing powers for their goal of world conquest. Twilight uses the books magic to reactivate the portal between worlds, allowing her and Spike to return to the parallel world. Twilight and the girls attempt to use the magic of their friendship to lift the Dazzlings spell, but it takes no effect. Concluding that they must perform a musical counterspell, the girls enter the Battle of the Bands to give Twilight time to complete the spell. The Rainbooms face hostility and sabotage from the bewitched bands throughout the competition, which raises existing tensions among Twilights friends over conflicting aspects of their band. Desperate for time in the semifinal round against Trixies band, Rainbow Dash performs an egotistical song to substitute the counterspell and nearly transforms, which forces Sunset to ruin her performance to keep her from exposing their plan to the Dazzlings. Despite this, the Dazzlings intervene to allow the Rainbooms advancement to the final round, goading a jealous Trixie into trapping the Rainbooms beneath the stage to take their place. Isolated for hours, Twilights friends enter a heated argument that allows the Dazzlings to absorb their magic. Realizing that their constant infighting is interfering with Twilights spell, Sunset convinces the girls to resolve their differences, while Twilight reasons that simply playing together as friends will make the counterspell work. Spike rescues the girls with assistance from DJ Pon3, a student whose headphone music protects her from the Dazzlings spell. DJ Pon3 provides a sound system that the Rainbooms use to engage the Dazzlings in a musical battle. Overwhelmed by the Dazzlings projected siren forms, the Rainbooms are joined by Sunset, who assumes her own ponylike form; with her help, the Rainbooms are able to destroy the pendants that provide the Dazzlings with their singing abilities, rendering the trio tonedeaf. Returning to its harmonious state, the school drives the Dazzlings away and praises the Rainbooms. Twilight and Spike return to Equestria, while Sunset uses Princess Celestias book to remain in contact with Twilight. During the closing credits, a montage plays showing Sunset being accepted by the student body and performing as the Rainbooms new lead singer and guitarist. In a postcredits scene, the human worlds version of Twilight Sparkle is shown investigating the strange activity around Canterlot High.