"In the year 1001 of the Celestia calendar, Equestrian scientists developed advanced magic making it possible to broadcast music over long distances. This innovation was called “radio,” and quickly became a sensation throughout Equestria. For a period of time, only one frequency playing classical music was available. This changed when a popular young disk jockey with the stage name DJ-P0n3 (born Vinyl Agatha Scratch) formally proposed the creation of an independent radio station called K-COLT. It was approved, with DJ-P0n3 as the host. In addition to playing rock-and-roll and other popular music, DJ-P0n3 also hosted the first Equestrian talk show known as 'The Vinyl Scratch.' These broadcasts were recorded for historical significance."
Octavia: Do you just…have a thing for alliteration or something? Vinyl: And the pony who just used a word I don’t understand is my lovely co-host, Octavia.
The Atoner: Princess Luna knows she screwed up way back when, and her attempt to reach out to Blueblood was part of an overall attempt to make amends for things. She gets royally ticked when she finds out it was Vinyl who guilt-tripped Celestia when she was the one who screwed up.
Vinyl: “That is the spirit of radio! There’s no limits! We’re here for truth, justice, and the power of rock and roll! It is our way! It is the only way! Even if we stop broadcasting, our signal will just travel across the universe forever! Stars fade away, comets burn out, black holes devour suns, but even out there in the black, ROCK will always live on! That means music will last longer than the heavens themselves! That is radio! That is K-COLT! And THAT. IS. THE VINYL SCRATCH!”
Berserk Button: If you mess with one of Octavia's friends, she will beat the crap out of you. If you mess with Octavia, Vinyl will call you a jerk, go out of her way to humiliate you, and then have security (the Diamond Dogs) beat the crap out of you.
Make false accusations about Celestia, and when Luna gets the chance to take it out on you, being deafened by the ROYAL CANTERLOT VOICE is going to be the least of your problems.
Bullying a Dragon: Vinyl spends the interview with Princess Celestia — the lady by whose good graces the radio show, and daytime, even exist— relentlessly badgering her about sentencing Luna to 1,000 years of boredom and loneliness on the moon, much to Octavia's horror. Though this dragon has family members willing to fight on her behalf. One's stupid and incompetent. The other…isn't.
Bunny-Ears Lawyer: Vinyl. She shamelessly teases, if not outright mocks, just about everyone she interacts with on the show, yet she's still incredibly popular and successful.
Cerebus Retcon: In Season 2 Chapter 3 lines delivered by Princess Luna show that Vinyl's attitude towards Princess Celestia in the first season's first episode was completely out of line and that Blueblood knows how much he's hated and that his life has become almost a living hell because of what Vinyl did during Season 1 episodes 3 and 4. For some readers those episodes are no longer funny because of the subtext that is now known.
Chewbacca Defense: Vinyl in Season 2 Chapter 2 applies this to Octavia upon hearing that somepony wants to do a Scooby-Doo-esque show starring her and her ensemble.
Octavia: What do solving mysteries have to do with music anyway? Vinyl: What don't they have to do with it? Octavia: …that's so stupid I don't know how to respond. Vinyl: Hurray, that means I win by default!
Crossover: At one point, Doctor Whooves Adventures did a crossover with the audio version, where they performed a Q&A session together. It was rather easy to set up, because the voice of the Doctor (The Jamjar) is also the director of the audio version of The Vinyl Scratch Tapes.
A Day in the Limelight: The entire story is one for the two mane characters. Also, Williams takes the other members of Octavia's ensemble (who are often ignored by the fandom) and gives them names, personalities and dialogue (except for Harpo Parish Nadermane, who's The Voicelessuntil chapter two of the second season to provide a Crowning Moment of Heartwarming).
Celestia (on the topic of imprisoning Luna on the moon): “T-that’s a bit out of context.”
Vinyl: “Fair enough. Please explain the context of hurling your little sister into the dark reaches of space.”
Snark-to-Snark Combat: The snark almost reaches critical mass when Vinyl and Octavia are guests on Blueblood and Trixie's radio show in Season 2 Episode 5. Literally everypony has a few sarcastic lines.
Defrosting Ice Queen: Octavia's Character Development throughout the story. She evolves from barely tolerating Vinyl's loud mouth and outrageous antics to realizing that she's really a good pony and becoming friends with her. Season 2 takes this further when they move in together.
Did Not Think This Through: Little Vinyl had a habit of swiping any musical instrument that caught her eye during her quest to obtain her Cutie Mark. When she found one that she absolutely loved, she decided to invite everyone to her concert performance, including that instrument's rightful owner, the local sheriff.
Prince Blueblood, who doesn't see any problems with outlining his brilliant plot to get K-COLT off the air in front of a huge, increasingly angry audience.
Flanderization: Prince Blueblood is turned from a shallow, snobby, self-absorbed Jerkass to a guy who lives to make everyone around him miserable through his inconsiderate excesses. The series portrays the Diamond Dog Rover in a less unpleasant light. For the record, in the actual show, Rover is an aggressive, foul-smelling, dim-witted, criminal slaver. As of Season two, however, he's been getting some Character Development.
Foregone Conclusion: Given the fic is based on in-universe recordings of the show and we're told it went on to become immensely popular and long-running, the efforts of Prince Blueblood to ruin it are doomed to failure.
Heroic BSOD: In Season 2, Episode 3, Vinyl suffers one after Luna gives her a massive What the Hell, Hero? speech for insulting her family, never thinking things through, and presuming she could talk on Luna's behalf to the ponies Luna hurt the most.
Instant Awesome, Just Add Dragons: Vinyl endorses this trope wholeheartedly while advertising Ponyville Library. She barely misses a beat after learning the dragon in question is a baby.
Is This Thing Still On?: Twice (that we see). They seem to have finally figured out how to know when they’re back on…three weeks after their first broadcast.
Inverted in Season 2, Episode 3 when Octavia tries to fill time solo by telling a slew of embarrassing stories about herself without knowing the station was off the air thanks to Luna losing her temper.
It's All About Me: If there's ever a competition for "who fits this trope best", Blueblood will win the grand prize.
Jerkass: Blueblood, even more so than canon. At least for a while.
Jerkass Has a Point: Subverted. Celestia acts like this is the case after Vinyl chews her out…but when she meets Luna, she makes it very clear Vinyl didn't know what she was talking about. And she is not happy.
Jerk with a Heart of Gold: This is how Spitfire describes Vinyl, after Octavia expresses doubts about her relationship with the DJ.
Spitfire: "Vinyl doesn’t talk about her feelings much, but she has them. She’ll act like nothing bothers her, laugh, and make fun of you…but she’ll also never tell you a lie, she’ll never cross the line once it’s been drawn, and she’ll never, ever, let you down when you really need her."
Octavia: Look, I will admit this is…creative…but you just can’t have an opera where nonsensical things happen for no reason! Vinyl: Clearly you’ve never heard a rock opera before.
Reasonable Authority Figure: Princess Celestia. When Vinyl takes her to task for banishing Luna to the moon, she realizes that the Jerkass Has a Point and goes to apologize to her sister. Later, in Season 2, Episode 3, Princess Luna proceeds to tell Vinyl that she deserved what happened to her and that her sister had nothing to apologize for, and now Vinyl has made her plagued with guilt over something that was Luna's fault.
"The Reason You Suck" Speech: Vinyl has been on both sides of this trope. She gives one to Prince Blueblood in Season 1, Chapter 3, and she receives one from Princess Luna in Season 2, Chapter 3.
Took a Level in Jerkass: Prince Blueblood is already a Jerkass in Canon, but in this story the character is worse than ever. First, he cancels Octavia and her ensemble's performances out of spite after Vinyl mocks him on air. Then, when Vinyl talks Octavia into holding an outdoor concert anyway, he locks Beauty Brass in "the fillies' restroom," then claims to be holding her hostage, with the deed to K-COLT as her ransom. He's made out to be worse than the Diamond Dogs, who in canon, are slavers (albeit stupid ones). However, as noted, he eventually does a Heel-Face Turn.
Villain Decay: The Diamond Dogs. They started out as a fairly credible threat in the main series, but have since degraded into dim-witted prank callers who are willing to humiliate themselves for steak.
Villain Team-Up: Beginning with The Stinger of Season 2, Chapter 1. Prince Blueblood, who's starting his own radio station to compete with K-COLT, talks with "The Great and Powerful" Trixie about becoming his co-host. In season 2, episode 2, their new radio station launches. And catches fire.
Vitriolic Best Buds: Vinyl and Octavia. The first story has hints that it may blossom into Belligerent Sexual Tension. Season 2 takes it past "hints" to become sub- (and periodically super-, around- and totally enveloping-) text.
What the Hell, Hero?: Vinyl's interview with Princess Celestia boils down to this regarding Luna's banishment, particularly for not trying to Take a Third Option during the incident and for never checking up on Luna even once during all that time.
Season 2 Episode 3 has Princess Luna give one right back to Vinyl for screwing with her family, especially for guilt-tripping Celestia over banishing her to the moon without learning all the details, namely how it was Luna who forced Celestia's hoof. IN FULL ROYAL CANTERLOT VOICE no less.
Season 2 Episode 4 has Trixie point out the double standards that go on.