Horse Ridin' (Motionless In White)

(For God's sake... do not take that title seriously. It's a reference to a hilarious old MIW video I've watched probably 100+ times)
When Rosaline and Sirenia were abandoned by their parents and left to their own devices, what other choice did they have then to live on their own? They raised themselves, taking care of each other through thick and thin as they grew up. And, eventually, they ended up being the proud owners of a horse farm. (as you do when you're orphans)
But when their coworker talks about bringing his brother and 'some friends' to an upcoming show the 2 sisters are competing in, who would have known it would be their favorite band?
(NOTE: This fanfic will be extremely hard to understand unless you have some basic knowledge of horses. It was pretty much written for me and the lovely April (who created the character Sirenia and told me to write this fanfic) so... well... read at your own risk. You may get really confused.)