There are tenors, and then there are the Irish Tenors. It's important to avoid confusion, because the group that will be performing at the Morris Performing Arts Center in South Bend on Friday is the group with the international following, the one that makes appearances on the major American morning television shows, the one that sells millions of albums worldwide. The rest may be tenors -- they may even be Irish -- but they're not the Irish Tenors.

The group's current lineup -- Finbar Wright, Anthony Kearns and John McDermott -- is not the original one. When the group formed in 1998, Kearns and McDermott were paired with another tenor, Ronan Tynan, because Wright, who was invited to join, had contractual obligations that kept him from becoming part of the group. When McDermott departed in 2000, Wright was able to fill in, and when Tynan bowed out in order to pursue his solo career earlier in 2004, McDermott returned to the fold for the group's fall tour, creating a sort of new/old roster that was original in spirit, even if it hadn't existed when the group was born.

The group's fluid, revolving-door makeup is attributable in large part to the popularity of its individual members, four charismatic singers who have made the Irish Tenors a part of their flourishing solo careers. Each of them is in demand both as part of the group and as a unique performer, and it is inevitable that a certain amount of juggling of priorities will occur.

"My cousin Bill Hughes is the man who started it all," Wright recalls of the birth of the Irish Tenors. "Bill has been a very successful TV producer in Ireland for many years. Back in the '90s, he was attending the Cannes Film Festival in France and had a chance to interview Luciano Pavarotti. Naturally, they discussed the Three Tenors concept. Luciano mentioned that Ireland was renowned not only for its great singers, but also renowned for some of the most beautiful songs in the world, and why not have a group of Irish Tenors who would perform that music?"

Hughes called Wright, who was under contract with Sony and unable to join such a group. He suggested Tynan and Kearns.

"Then, of course, John McDermott was already an established star in North America, and his involvement was a key factor in the successful launch of the group in the U.S. and Canada," Wright said. "A year later, Bill's original wish came true, and I joined the group."

Kearns, the only constant member of the Irish Tenors, was born in 1971 in a small village in County Wexford, Kearns nurtured his early love of traditional Irish music, becoming an accomplished amateur practitioner of the traditional a cappella style commonly called "shut-eye songs."

Kearns gained national attention when he won a competition called "Ireland's Search for a Tenor," a stunt timed to coincide with the Bank of Ireland's release of a new 10-pound note (a "tenner," in the local vernacular). His winning performance ended with an encore of "Danny Boy," the world's favorite Irish song.

McDermott's family hails from Glasgow but emigrated to Canada in the 1960s. McDermott now makes his home in Toronto and Boston, but his musical loyalty is 100 percent Celtic, half Irish and half Scottish. He strives to bring the tradition of Celtic musical storytelling to the group's repertoire.

"John McDermott is one of the funniest men I know," Wright says of McDermott's lighter side, "and, only for the fact that he is such a compelling singer, I am sure that he would be a roaring success as a comedian. As they would say in Ireland, he is a tonic and a wonderful asset for the group. He is hugely experienced as an entertainer and is totally committed to delivering the best for the audience who come to our concerts."

Wright, the newest original member of the Irish Tenors, and perhaps the most visible one, came to the group through the most unusual channel. Born in 1957 in the town of Kinsale, Wright showed an early passion for singing, performing with his four brothers beginning when he was 6 years old and eventually joining the choir at Maynooth College. In 1978, he sang solo during the pope's Mass in Dublin's Phoenix Park in front of an audience of 1 million. Yet, in those days, music took a back seat to Wright's more urgent calling: He was studying for the priesthood and at the age of 21 was ordained. In the end, music proved to be Wright's true destination, and after leaving the priesthood in 1989, he built a successful career as a solo singer and TV host.

These three tenors, although all undeniably Irish, hit their real international stride when their music conquered America. A 1998 PBS special introduced the group to an American audience, and soon a ravenous North American hunger for the tenors' music developed. When, after Sept. 11, a bagpipe version of "Amazing Grace" became the American national expression of mourning, suddenly nothing seemed more American than Celtic music.

The Irish Tenors were in demand at patriotic functions: Tynan, whose inspirational biography (he is a double amputee, a Paralympics gold medalist, a medical doctor and a world-renowned singer) seems almost too American to be true, was especially sought after. He sang "Amazing Grace" at Ronald Reagan's funeral and became a fixture at New York Yankees games, belting out "God Bless America" during the seventh-inning stretch. The other Irish Tenors have proved themselves masters of Americana as well. They, too, have performed inside Yankee Stadium, and Kearns and Wright sang "Amazing Grace" outside the Capitol Building, in front of "Good Morning, America's" cameras, during President Reagan's funeral.

"It is always a great honor to be asked to perform at a historical moment in the life of a nation, especially a nation as majestic as the United States," Wright explains, describing the Reagan funeral as, for him, the most memorable event of the past year.

"We took it as a sign of our status in the United States as able ambassadors for our country, and we are proud of that and proud of the excellence that we seek in each performance that we give."