This one would have to be one of the simplest ones since the original song didn't have too many layers. This is Dark Horse by Katy Perry

Applejack - Alto 2 (Lowest part)
*Bass Line
Twilight Sparkle - Alto 1 (Second Lowest Part)
*Percussion
Rainbow Dash - Soprano 2 B (Third Lowest Part)
*Harmony 2
Pinkie Pie - Soprano 2 A (Third Highest Part)
*Harmony 3/Percussion
Rarity - Soprano 1 B (Second Highest Part)
*Lead Vocals 
And Fluttershy - Soprano 1 A (Highest Part)
*Harmony 4

#Mane6Acapella​
#Rarity​
#MuseScript