Okay, so it's more of a quartet, but you don't see too many "quartet" song searches when it comes to pony remixes. :) 

So yeah, what happens when you take the catchy (if not somewhat creepy) song "It'll Be Okay" from FiW episode 8 and do a bit of vocal genderswapping in Garageband, add it with the original vocals, and do a bit of interchanging mixing?  This! 

The words like "brother" and "he" weren't changed as a genderswap thing because I just used the Female-to-Male effect (and vice-versa) in Garageband to do this.