Operatic baritone Nathan Gunn has performed so frequently in Washington it is surprising to learn that his Washington National Opera, or WNO, concert Sunday is his debut with the company. Ever since honing his talents the summers of 1994 and 1995 as a member of the Wolf Trap Opera Company, he has performed for audiences all over the world with a repertoire that encompasses standard and new operas, recitals, Broadway classics and cabaret.

From Papagena and Figaro to Billy Budd and Clyde Griffiths in "An American Tragedy," he becomes each character with astounding ease.

"I love the anticipation of choosing music for a mostly opera-loving audience in Washington, one of my favorite cities," he said. "My choices for this concert are diverse with some Rossini, Mozart, Sondheim and a few surprises. I'm dedicated to accurately reflecting what I've been doing by singing some opera standards and mixing them with some musical theater pieces.

Washington National Opera Celebrity Concert Series: Nathan Gunn
Where: Kennedy Center Opera House, 2700 F St. NW
When: 4 p.m. Sunday
Info: $25 to $180; 202-467-4600; 800-444-1324; kennedy-center.org

"It's important to me to show the similarities between American stage music and European theater, which is opera. For example, I'll show the connection between the two musical forms by comparing Leila in 'The Pearl Fishers' with Lily Craven in 'The Secret Garden.' My friends, tenor William Burden and Ted Sperling, who is conducting the WNO orchestra, will join me. The encores will be songs my wife and I put together."

Following his WNO debut, Gunn will sing the premiere of a song cycle by Augusta Read Thomas with the Orpheus Chamber Orchestra, then immediately change pace, launching into a program of romantic duets from Broadway with Kelli O'Hara, conducted by Sperling. His schedule for the rest of the season is jam-packed but exhilarating. The first of three operas he performs is "La Comte D'Ory" at the Met in January. Next comes a Dallas Opera production of Dominick Argento's "The Aspern Papers" in April, and in June the world premiere of "The Gospel of Mary Magdalene" by Mark Adamo for the San Francisco Opera.

"I love variety and always look forward to new operas. The character must be someone I can relate to in order to invest myself in the discussions. The most difficult role to get into was Father Delaura in 'Love and Other Demons' because he was in love with a 15-year-old girl. Sometimes the score is not yet written. Although I'm a risk taker, I must know who the composer is, who the librettist is, where it will be performed and who the conductor is. Once I know the voice range and orchestration, I'm deeply involved in the process."