Lost music purchased on itouch after synced to computer-help

I had bought a lot of music on my iPod touch and it was clearly in my "Purchased" playlist on the ipod. When I synced my iPod to my computer, not only did the "puchased on iPod" music not transfer to the computer, but it completely disappeared from my ipod. All in all I lost about 60 songs. I cannot find them on my computer, although it says I have already purchased the songs. They are not in "my music" folder in my computer, and it does not show up in any folder when I do a thorough search. Is there any way I can acquire this music again?