Juicy Drop: I can't believe this! I get to interview the Chopin! Journalists from here to Hoofington Heights would give their left wing for the chance and you give this to me?
Editor: Well, we hope it'll give you the… experience you'll need to get through the job.
Juicy Drop: Well, you can count on me, boss! I will dig up all the dirt I can.
Editor: …Yeah, you do that.
[Later]
Juicy Drop: G-god afternoon, Mr Chopin!
Serenade: [Smile] There's no need to be so formal. Chopin is just fine.
Juicy Drop: Hm? No nicknames? That's fine though I hope by the end of the interview, we'll be close.
Serenade: [Nods] Hm.
Juicy Drop: So how about we start with-
Serenade: Oh, question, did you sign the agreement?
Juicy Drop: Agreement?
Serenade: All interviews with me have to respect my private life in some regards. I can't let things that ruin my image get out, you see.
Juicy Drop: B-but we're a rag magazine. Surely you know that-
Serenade: So is that a no?
Juicy Drop: …I guess we could steer clear of… certain topics.
Serenade: No need for that. I just ask that you no publish certain things I say and in exchange, I'll be 100% honest with you.
Juicy Drop: …So I get free reign to ask anything, even the most private details on your life and you'll answer them all honestly? No lies or misdirects?
Serenade: Not a one. But I get to chose what is published, no sneaking behind my back and publishing my embarrassing secrets. Deal?
Juicy Drop: [Thinking] He really plans on taking my word for it? He's surprising naive. [Out loud] Of course, we journalist have integrity!
Serenade: Then lets shake on it. [Horn glows]
Juicy Drop: [Shivers] E-eh? What was that?
Serenade: Just a bit of insurance. Now, your questions.
*
Serenade is a very secretive pony, despite being a celebrity. He tries his best to be what the crowd wants him to be but at times, it gets hard so he came up with a way to keep ponies honest with him. He calls it his Promise Spell.
After years of perfecting it, he generally uses it on nosy journalist who try and find scandalous things to print about him. Most are lies but some are truths that would ruin his image. The spell is simple, make a promise with an equal exchange and agree to the deal. Once the deal has been accepted, his spell enters another pony and makes them keep that promise.
To create a spell that is basically permanent (the spell will disappear if he breaks his promise to the one he cast the spell on) is a difficult thing to do and impressed Princess Twilight when he showed her his skills. She advised against using the spell since it violated ponies free will and he agreed. In the hooves of worse ponies, such a spell would be devastating but Serenade only uses it to keep his image clean and rag magazines off his flank.