Beautiful and elusive baroque piece
 

I picked this up off of a program like limewire and I know it was mislabeled. The original was labeled as 'Pachelbel Canon, Baroque F-P' and had other composers listed. None of which were actually correct. I tried checking is maybe this was an obscure piece from Pachelbel despite it being so beautiful i'd expect it to be more known, but I couldn't find anything...I do know it's baroque, though, just from the sound and the trills and techniques...So I guess that narrows it down some...
By the way, the picture is just something random I found on my computer, I know it doesn't fit the music much save for the music having a slightly dreary and dark feel. It was one of the only things that wouldn't be inappropriate(hanged people, lions feasting on other animals, death pictures)

That's the 2nd movement (Arioso) from Concerto for Flute & Orchestra in D Major by Johann Joachim Quantz.

Ah, you beat me to it. I played this concerto on flute in front of a paying audience a couple of years ago - it was a pretty fancy event :)