WHAT should you do if you want to dance with Austrian princesses, sing on the streets of Moscow and perform at Carnegie Hall?

You should join the Krokodiloes, Harvard's eldest a capella singing group.

This Sunday, the Krokodiloes will join a capella groups from Yale and Princeton to sing at a benefit concert at Carnegie Hall to celebrate World Food Day, with the proceeds going to the Interfaith Hunger Appeal, a group committed to providing food to the world's poor. The show, which will be emceed by Tony Randall, has already sold out the 2500-seat auditorium, says Jan C. Larsen '89, general manager of the Kroks.

Members of the all-male a capella group say they are excited to be able to perform at the famous concert hall. "It's about the most exciting thing we'll do musically this year. [Carnegie Hall] is one of the two best concert halls in the world," says Paul M. Lincoln '90. "We've already played the Musikvehrein [in Vienna], so I guess this is it."

Group members also say that they will enjoy singing with the Yale Whiffenpoofs and the Princeton Tigertones again. "They are fantastic groups. They are always musically excellent," says Kevin M. O'Halloran '89.

Larsen says that there is little rivalry between the collegiate groups. "We're all out there to make music," he says. "The only rivalry is that we want to be better--we certainly don't want them to be bad."

Though the three groups have performed on the same bill before, the Carnegie Hall concert will mark the first time that all three will sing a song together. The concert will close with a performance in unison of a spiritual called "By and By." Larsen says that although the groups have been rehearsing the song individually, they will not get to practice together until right before the show. But he adds that he envisions few problems because of the song's simplicity and the singers' talents.

Other benefit concerts at which the Kroks will perform this year include one for volunteers at the Boston public schools and one for the Jimmy Fund's "Evening with Champions."

Of course, the Kroks usually sing for profit--as often as two or three times a week during the school year, O'Halloran says. Alumni donations and revenue from these gigs are the 42-year-old group's sole sources of income--and the means by which it has toured each summer since the 1960s. Larsen says that the Kroks are so well-known from their tours that they get invitations to perform from the likes of the Austrian royal family, the American ambassador to Switzerland and the Japanese parliament.

THIS summer, the Kroks went on a world tour which lasted two months--and brought them behind the Iron Curtain for the first time. The singers say they especially enjoyed singing on the streets of Moscow.

Though originally their Moscow tour guide had them singing for tourists, the Kroks decided to take their act to the Soviet people themselves, says Thomas A. Shields '89. "Usually when we sing on the street, we can't do our quieter ballads because of all the noise. But the people there were so attentive. We sang every song we knew," he says. "I remember that afterwards, a really big guy came up to me and pointed to himself and said, 'Andre.' Then he pointed to me and said, 'Good.' I think that may have been the only English he knew."

Lincoln says that the Kroks attracted a crowd of 300 to 500 people on the Moscow streets for both of their impromptu performances. "It was touching," he says.

"I think they were the best audiences we performed for on that tour," O'Halloran says of the Muscovites, who gave the Kroks flowers, pins, ribbons and paintings after their songs.

The tour also took the Kroks to such cities as London, Paris, the Hague, Monte Carlo, Salzburg, Hong Kong and Tokyo. Lincoln cites as his favorite part of the tour the group's performance before an Austrian princess, who invited them to a party after the show. "It's just hard to believe that we were there dancing with princesses in the middle of the Alps," he says.

BEING a Krok is "the most intense musical experience you can have at Harvard," O'Halloran says. "We practice two to three times a week during the school year, and we perform together over the summer. We're together all the time--we become a family."

Harvard students who didn't catch the Krokodiloes in Moscow or weren't quick enough in snapping up the $100 tickets to the Carnegie Hall concert will be able to see them perform with the Whiffenpoofs, the Radcliffe Pitches and the Yale Whim-N-Rhythm at Sanders Theatre after the Yale Game on November 19. "It'll be almost just like Carnegie Hall, but right here in Cambridge," Larsen promises.