I don't know how I feel about this episode, from what I remember of it, seems that Pinkie Pie was very inconsiderate toward both her friends and her neighbors with the whole play the Yovidiphone or whatever that instrument is called, causing them sleep deprivation and that interfering with their important day to day duties, and poor Fluttershy fell asleep in the daytime because of this.
and look, I don't like criticizing the actions of characters in the show, but for honesty sake, sometimes I feel obliged to bring it up. This whole situation feels awkward, me being one of the fans who daydream and wish they could be in Equestria as our OCs, that's the reason I started my fanfic, not because I am a good writer, I probably suck at writing regardless, with not being an academic and all, but even with that issue brushed aside, I have personality flaws of my own, and I've caused people hurt before, wished I could have done otherwise, and it was too late, all I can do is learn and listen to others.
It hurts, to have to say this about fictional characters I admire so much, but the truth is, Pinkie Pie was out of line in this episode. Pinkie Pie is still a fun loving character who has helped save Equestria from villains who tried to rob their citizens of their freedom, so she deserved a chance to be made to listen to concerns of others, about the impact her obsession with her musical instrument was having on others, however at the same time she earned bad marks for this one and probably should have received some sort of disciplinary action from Twilight Sparkle, what her punishment should have been, I cannot say, nothing extreme like exile or a loss of friendship, more like, Twilight Sparkle to give Pinkie Pie a stern talking to and a warning about it, but it is clear that what Pinkie Pie did was wrong, expressing her passion for music is not the issue, the issue came in when she disturbed her friends with it.