During at least two performances on Vail Mountain, the Georgetown Phantoms will embrace their namesake. The 19-member a capella group from Georgetown University got its name back in 1988. "A group of students in the gospel choir wanted to start a caroling group," said Nick Oki, a member of the group as well as the business manager. "They'd pop up around campus and sing. One of the Jesuits saw them and said 'You guys appear like phantoms.' That's how we got our name."On Sunday and Monday the group will perform on Vail Mountain; on Monday be at Mid-Vail and Tuesday, at Eagle's Nest. There's no set time for the performance, though mid-day is a good bet."We'll just sort of pop up," Oki said. If you want to be sure and see the group, the best bet is to come to the Four Seasons in Vail tonight. The Vail Symposium hosts a concert by the group, which begins at 6 p.m. "Bringing an a capella group to Vail for the holidays has become a tradition for the Vail Symposium," said Liana Moore, the executive director of the Vail Symposium, and one of the people instrumental in bringing the Yale Whiffenpoofs to Vail last year. "Our mission is to provide educational opportunities for the community, so the Georgetown Phantoms will also be speaking about the a capella tradition at Georgetown University and how they arrange their own music," Moore continued. "It will be an entertaining and educational evening."Everything but technoThe co-ed a cappella group has a repertoire of more than 50 rock, pop and R&B songs."We sing mostly contemporary, well-known stuff. Some of our favorites right now are 'Domino' by Jessie J, 'Home,' by Phillip Phillips, 'Love On Top' by Beyonce and 'Bad Romance' by Lady Gaga. We also have a Motown medley we sing quite often that's been in the group a long time."The group votes on which new music - somewhere around nine songs a year - to add to the repetoire each year. They look for harmonies and certain instruments that are easier to replicate with the human voice. "Lots of songs that are popular right now are techno, which is harder to sing." Oki said. The group is one of nine a capella groups on the Georgetown campus, Oki said. "It's always a struggle to figure out which group is singing which song," he said.Yale University has 14 such singing groups, and groups can be found at plenty of other East Coast college campuses."It's viral over there," Oki said. Breaking new groundThe group recently sang at a midnight premiere of the movie "Pitch Perfect," a movie about a college all-girls singing group. "A capella is getting huge," Oki said. "The Sing Off was huge, and The Voice. There are all of these shows on television. With this movie, it was new ground that's been broken."The Phantoms recently sang at the White House for Christmas. "It was our second year in a row doing that," he said. "A little after that we sang at the Blair House, which is the White House guest house. We were singing for the National Security Council's holiday party."Generally the Phantoms tour along the New York coast. So how did a Vail tour come about? Oki's brother was the manager of the Yale Whiffenpoofs who performed in Vail last year, so connections were already in place. "He paved the way for me," Oki said. "The Yale group tours much more than Georgetown, which I'm trying to change. We wanted to branch out from the East Coast and this was the perfect opportunity."High Life Editor Caramie Schnell can be reached at email@example.com.