Pianist-conductor Walter Nowick is crusading to save the world from nuclear holocaust by performing the glorious music of Verdi. Joined by the 80 members of the Surry Opera Company, Nowick pleaded his case Friday night at the Wolf Trap Barns.

One of the foremost Zen masters in the United States, Nowick happily led the small Buddhist farm retreat of Moonspring, Maine, until he saw a broadcast of "The Day After," the television movie depicting doomsday. Shaken by its vision of the planet's destruction, Nowick gathered singers, trained and untrained, from surrounding communities to perform Verdi's melodic and accessible masterpiece, "Aida." It is, he reasoned, the perfect opera in which people of all abilities can participate (even the audience helps sing the grand finale of the second act).

By performing this work, the singers hope to communicate their commitment to preserving the world so future generations may experience the joy of music-making. At Friday's performance, the chorus and six soloists were accompanied by Nowick, Deborah Moscowitz and John Haskell on duo pianos. The basic set was slides of watercolor renderings of Egyptian temples flashed on a screen next to the choristers.

The performance was mostly blood, sweat and tears -- an act of love, if technically imperfect. The role of Aida was shared by Nancy Ogle, who sang the first half, and Kathy Sikkema. Ogle is the more confident performer, possessing a strong, vibrant voice and remarkable sense of phrasing, although Sikkema sang her part with dramatic conviction. Sheldon Bisberg's Radames was a well-balanced portrayal, emotional yet controlled. Beth DeMeyer relished her part as Amneris.

An intriguing aside: the large white barn at Moonspring that serves as a concert hall inspired Wolf Trap's founder, Catherine Filene Shouse, to create her Barns here.