Can you please help me with this song?

This is driving me crazy. There's this piece that I know very well. I've even played it, but I just can't remember the name!!!!!! I have found a video but am unable to get the name.

http://www.youtube.com/watch?v=aPIWBBOpCvc

This is a weird arrangement, you may have to listen for 30 sec to hear the song.

"Light Cavalry Overture"
http://www.youtube.com/watch?v=X34Ujm8FnMQ