Put way to much time into this, but I made it work! I know it's not Rarity's singing voice, but it's more of her speaking voice as portrayed by Tabitha St. Germain.
I feel like this, as well as many other 80's pop rock songs fit Rarity perfectly. I mean this song literally has "Rarity" as one of the lyrics.
This took a lot of time and effort to do, so enjoy!