As ambassadors, Yale University probably has no better emissaries than the Whiffenpoofs, the school's world-famous a cappella group.

The group, which turns 100 this year, is comprised of 14 senior Yale men, who in a final stop in a 10-day tour, gave a rousing hour-long performance at The Ellis School in Shadyside last night.

"It's really something special to see them perform," said Mary Grant, principal of The Ellis School, which first hosted the famous group three years ago.

The story goes that the Whiffenpoofs started as a senior quartet in 1909, meeting weekly for singing sessions at Mory's Temple Bar, the famous Yale Tavern.

The sessions, which spawned what is now a very selective cast of performers, started out as a way to cope with harsh wintry nights in New Haven, Conn., according to the group's Web site.

To celebrate a century, the group has just completed the first part of a winter tour that took them to the White House and through small and big churches and schools from Mississippi to Tennessee.

Standing in the foyer of The Ellis School yesterday, Yale student Jesse Obbink, a tenor from East Lansing, Mich., reflected on the rich history and the tradition of the group, and what it means to be a "Whiff."

"It's an awesome responsibility. We are ambassadors of Yale. One of the things I enjoy most about our tours is that we get to meet people who see us as more than just Yale students," said Mr. Obbink, 22, who is majoring in cognitive science.

For Jamie Warlock, a tenor from Washington, D.C., belonging to the elite singing club -- even among Yalies -- "is all about the experiences we share with and gain from the people we meet on the road."

The group will soon embark on a year-long tour schedule that will include not only parts of the United States, but South America.

"The Whiffs have performed on almost every continent, since we have been in existence," said Mr. Warlock, 22. "My favorite moment, so far, is when President Bush asked us for an encore."