It's not the usual competition where sororities and fraternities vie for the best recruits, or when nervous freshmen ponder whether they'll make the cut.
When the shouting there is over, it's all about singing, as CBS News Sunday Morning's Rita Braver discovered. The student body is part of a cappella rush.
The phrase "a cappella" is derived from Italian, meaning "in the style of the chapel." It is music made only by voices -- no instruments. And it is one of the hottest movements on campuses all across the country.
There are almost 1,000 groups nationwide -- 15 at Yale alone. Some are coed and others single sex, and they sing everything from top 10 hits to old favorites.
Tradition has it that collegiate a cappella started at Yale at Maury's Bar in 1939. A handful of Yale men decided to start a club that would sing for drinks. The Yale University Whiffenpoofs have been singing ever since.
Open only to senior men at Yale, the Whiffs have some pretty famous ex-members.
President Bush's grandfather was a Whiffenpoof. Neither President Bush, however, was a Whiff. But, Marc Freed Finnegan, the group's business manager, still has plenty of bragging rights.
"The tradition is that each year a new Whiffenpoof group has their initials carved into a table," says Finnegan. "Cole Porter is right over here, and he was in the class of 1918."
And every Yale a cappella group is steeped in its own tradition, which can be a bit foreboding to aspiring a cappella singers such as freshmen Zach O'Mally Greenburg, Rebecca Bloom and John Bittner.
"I haven't had a single afternoon off since the whole thing started," says Bloom.
"I ended up auditioning for nine [groups]," adds Greenburg. "Because I really didn't know what I wanted, so I figured, you know, the more the merrier."
The auditions could be stressful.
"You're not really sure whether they want you or you want them, or some strange combination between the two," says Bittner.
How do you get into an a cappella group? Sunday Morning asked the Dukesmen warming up for rush in bandannas and war paint.
They say the best singer has the best chance of joining the group. But in a perceived college culture of drugs and sex, why join an a cappella group?
"I think one of the sexiest things on earth is to see 16 hot men on stage singing to you," laughs a cappella member Chris.
No one really knows exactly why collegiate a cappella has become so popular in the last decade, but there's big competition with so many groups on so many campuses.
At the University of North Carolina in Chapel Hill, the Loreleis sing up a storm, trying to attract paying customers to their big show. It can be hard work. With nine groups on the campus, non-singing students sometimes complain. Some say they're tired of hearing the '80s pop music. But members of the a cappella group say they get support for their singing.
Matt Susong of UNC's Clef Hangers readily admits part of the attraction of performing a cappella is that it can make you a campus star.
"To be at a school where I can go to a party or to a bar the next night and have people come up to me and actually know who I am -- like I'm a basketball player or something like that -- it's really special," says Susong.
The pressure was on for the Yale freshmen in the hours before tap night, when they'll know which a cappella group will invite them to join.
"I've been putting off my nervousness all week," says John Bittner. "I mean, anything could really happen."
Behind the scenes, the groups were prepping and primping. They were trying to be the first to get to the dorm rooms of their top picks. Each new member drank from a loving cup with punch certified as non-alcoholic by the rush co-chair.
By 10 p.m., all of the runners were massed behind High Street Gate. And soon, they were off.
A cappella at Yale is so sacrosanct that the University wouldn't let Sunday Morning follow the kids into the dorms.
But confidential sources and videotape showed that Zach O'Mally Greenburg, Rebecca Bloom and John Bittner got in, coincidentally to the same group: Out of the Blue.
For Further Information:
Directory of College A Cappella Groups
International Championship of Collegiate A Cappella
Best of College A Cappella compilation CDs
Collegiate A Cappella CDs for sale
The Contemporary A Cappella Society