Wow, it is great to see so many different instrumentations of pony songs! I can tell that This Day Aria has a lot of fans, since it's being arranged by so many folks. The more, the merrier, as far as I'm concerned.
The latest version comes from frequent contributor Dimondium, and it's an arrangement for This Day Aria on clarinet. As always, Dimondium did a great job on this piece. Find it here on Noteflight. Clarinet players, try it out and let us know what you think!