Octavia is a young up-and-coming piano master, hailing from a Canterlot family who has bred some of the best piano players in all of Equestria.
Vinyl is a young, wayward unicorn, born in Ponyville. She's a troublemaker who loves music but can't find her instrument.
They come from entirely different circles. So how is that the two ponies who loathe eachother at first sight, come to help eachother gain their cutie marks; and maybe even become friends?