In opera, a little knowledge can go a wrong way. The Foundry Opera Group gave itself a benefit gala concert last night at the Foundry Methodist Church in downtown Washington; with the best of intentions, the group turned some of the most beautiful pages of opera into bad high camp.

This was not a concert of operatic arias, but a series of "staged" complete scenes from "Carmen," "La Traviata," "Werther" and "Madama Butterfly." Since the printed program prudently failed to mention the name of the director, one could assume that they were improvised, as were the sets. Far be it for anyone to point an accusing finger at limited resources, but some sort of finger must be pointed at lack of taste. Cio-Cio-San's trousseau included Violetta's dying gown, and her table was decorated with period touches like an 8-by-10 glossy of the tenor in a turtleneck sweater. The acting was embarassing.

All of which brings us to the singing. Attending amateur opera concerts is a bit like working in the mines: You have to go through a lot of dirt before coming up with a bit of gold. Were it not for sopranos Elizabeth Aubry and Linda Marquart, the evening would have been the sort of totally naive occasion with which Susan Sontag defined the meaning of camp in the mid-'60s. oYet Aubry and Marquart rose above their surroundings, their talents begging for a better setting.

Marquart was a soubrette Violetta, negotiating the Act I finale with ease and style. Aubry sang a full-voiced, dramatic Butterfly, unsteady but naturally beautiful; she also displayed legato, something that eluded the rest of the young singers. Comprimaria mezzosoprano Mary Perriello's voice and operatic pressence suggested that she may have a future in punk rock.

The program will be repeated tomorrow at 2 p.m., at which time we suggest attending the Wolf Trap Opera Showcase instead.