My alma mater does it a little differently:
Greek Sing
Greek Sing is an annual event in which the fraternity and sorority community at Carnegie Mellon participate. The event is sponsored by Greek Council and is the Greek community's largest annual philanthropy event. In Greek Sing, fraternity and sorority chapters perform collections of songs or excerpts from a musical or an original script. The event is held at Soldiers and Sailors Memorial Hall in Oakland, and all proceeds are donated to a charity, which is selected each year by members of the Greek community.
This year Greek Sing was held on March 24, 2007.
http://www.flickr.com/photos/cmugreeklife/sets/1326723/