Summer and Strauss made a winning combination as conductor Franz Allers and the National Symphony, with the aid of a lively trio of singers, demonstrated at Wolf Trap last night.

Allers' genial podium manner set an easy and engaging tone for the evening. Though a bit heavy-handed and inclined to indulge the orchestra at the expense of the singers, he brought flair and experienced pacing to the program. After intermission, he also offered a witty capsule history that made it perfectly clear how to keep Strausses straight.

In the opening excerpts from Richard Strauss' "Der Rosenkavalier," the Korean mezzo-soprano Shinja Kim began with a line of thrilling focus and projection. A highly talented young singer definitely going places--she makes her New York City Opera debut this fall--she brought a remarkable depth of characterization to her portrayal of the young Octavian in the few brief scenes. The deep-throated quality of her sound and the consistency of her voice throughout its range gave her performance a special excitement.

Sopranos Mary Shearer as the Marschallin and Elizabeth Hynes as Sophie handled their roles with insight and skill. Despite an initial tightness in Hynes' voice and a tendency to overlook details on Shearer's part, the two formed a sympathetic trio both vocally and expressively with Kim. To end the evening all three participated in an ebullient "Die Fledermaus" excerpt, followed by the opera's overture, exhuberantly realized by the orchestra.