A cappella music is music which is performed without
instruments; only the
human voice is used. Originally it was the realm only of
barbershop music,
Gregorian chant, and other similar venues. Today, however, a cappella has taken a new turn and is sweeping the nation's
colleges. Although there are many
Old Guard groups which focus on
doo-wap and other older styles, but more and more groups are turning towards
pop music arrangements.
Many people are turned off by the idea of people turning their favorite songs into a cappella, but often the result is suprisingly entertaining. In my personal experience, a good a cappella group can add an amount of value to the song they're singing just in the way they look while performing it. Also, it's amazing how well people react to a bunch of dudes singing and dancing to a Britney Spears song.
This new style of a cappella is most prevalent on the East Coast, where many colleges, some as small as a couple of thousand people, have upwards of 10 acappella groups. In situations like this, the groups end up doing a sort of draft pick audition, wherein each auditioner performs in front of representatives from every group simultaneously. Naturally, this tends to spread out the talent evenly between groups, which, IMHO, results in an overall drop in quality for all of the groups involved.
In the midwest, a cappella is growing rapidly, although it's still not quite as popular as in the East. For instance, at the University of Illinois, there are only around 5 groups, each with it's own unique style and sound. However, the school is huge, with around 26,000 undergraduates alone, so this gives the groups a much better shot at getting a lot of extremely talented individuals.
There's a big competition every year for college a cappella groups, called the NCCA, or National Championship of College A Cappella.