It's a promo for a independent "arranged album" of the Tsukihime game music - and a nice one at that (the album in general, that is, but the music for this trailer is exceptional good, in my opinion). Here it is, provided in lo-fi and hi-fi, though both might be a bit much for narrowbanders:

High (http://mirror.fuzzy2.com/LittleWing/7thmoon.mpg)
Low (http://mirror.fuzzy2.com/LittleWing/7thmoon_s.mpg)

Enjoy :music:.