Of all composers from which musicians and musicologists may hope to unearth a previously unknown work, Richard Wagner is certainly low on the list. An immensely popular composer both within his lifetime and consistently so afterward, there has been so much interest in his life and music that the chances of bringing one of his works to a concert hall for the first time almost 120 years after his death would seem extremely slim.

Yet the Juilliard Choral Union distinguishes itself this spring by performing what is quite probably the United States premiere of a four-part choral fugue by Richard Wag ner, Dein ist das Reich. Judith Clurman, director of the Choral Union, conducts the chorus (with orchestra) in a concert on April 5 in Alice Tully Hall at 8 p.m. The concert also features Beethoven’s Mass in C and Elegischer Gesang, and Wagner’s Siegfried Idyll.

Wagner wrote the fugue as a 20-year-old student, under the tutelage of Theodor Weinlich. While it is one of his earliest pieces to have come down to us, it was only published for the first time in 1983, by Hänssler-Verlag. Clurman, who was recently named Juilliard’s director of choral activities, recalls: "I found the piece in Vienna, at Doblingers…it is the only place in the world that has everything in stock, and it has a very knowledgeable woman who knows every piece of choral music and every edition printed."

Prior to his counterpoint instruction with Weinlich, Wagner had mainly written piano and symphonic music, and even a string quartet, much of which

Although this early work of Wagner’s sounds little like his mature style of composition, his genius is apparent even in his youth.

is now lost. This fugue marked a turning point in the young composer’s career. Wagner wrote about his counterpoint studies in his autobiography, saying that, because Weinlich made him "write proper vocal parts for [the fugal exercises] below the staff, my feeling for vocal writing had been awakened in this manner."

Wagner’s subsequent career in vocal writing is, of course, extraordinary. And while this fugue sounds little like Wagner’s mature style of composition, his genius is apparent even in his youth. Such fluid and musical writing in complicated counterpoint from someone barely out of his teens shows that "the man has promise," as Clurman joked recently in a rehearsal.

The Juilliard Choral Union is the School’s volunteer chorus offered through the Evening Division; this concert will close its second season. In those two seasons, the ensemble has distinguished itself with performances of Mahler’s "Resurrection" Symphony in Carnegie Hall with the Juilliard Orchestra; Bernstein’s Chichester Psalms and the Fauré Requiem in Alice Tully Hall; and Stravinsky’s Symphony of Psalms in Avery Fisher Hall. The chorus also participated in the Juil liard Opera Center’s acclaimed production last season of Dialogues of the Carmelites under the direction of Frank Corsaro and the baton of Julius Rudel, and was featured in the annual Lincoln Center tree-lighting ceremony in December.

"After only two years, the chorus is really able to do some amazing things," said Jesse Tampio, a bass who joined the Choral Union this season. "It’s very exciting to think that we’ll continue to be doing these kinds of premieres and collaborations."

Free tickets, which are required for this concert, are available beginning March 22 from the Juilliard Box Office.

David Ezer is conference manager for Chamber Music America, the professional service association for chamber music, and a member of the Juilliard Choral Union.