A Cappella Groups: With Friends Like These, Who Needs Instruments?

Singer-dancer Corey Vidal turned himself into the latest YouTube celebrity by posting an a cappella tribute to composer John Williams. In the video, the 21-year-old Canadian appears to sing all the parts of a four-part-harmony arrangement (in separate boxes on a divided screen, "Brady Bunch"-style).

The musical medley sets "Star Wars"-themed lyrics (including Wookiee growls!) to music from "E.T.," "Raiders of the Lost Ark," "Superman" and other films scored by Williams, the sci-fi soundtrack master. It is everything a cappella music should be: vocally impressive and undeniably nerdy, a tour de force performance (pardon the pun).

Of course, Vidal later clarified that he was lip-syncing (still a pretty neat trick) to a recording by Moosebutter, an a cappella quartet from Utah. But Vidal's video continues to be a hit, garnering more than 2.2 million hits since it debuted last month.

Does this hint at a renaissance for a cappella music? One need only look to YouTube for the answer; a seemingly endless parade of college a cappella group videos are posted. Here we judge a sampling of them on these criteria: name (bonus points for puns), wardrobe (color coordination) and stage presence (a little movement goes a long way). Oh, and singing talent, too.

University of California at Berkeley: The UC Men's Octet, "Bohemian Rhapsody"

Name: Boring. Where's the groan factor?

Wardrobe: Matching suits and ties. Sufficiently dorky.

Stage presence: All the Queen references you'd expect and wildly over-emotive acting. Four stars!

Singing talent: Top-notch musical theater.