THE WASHINGTON OPERA has mounted a stunning new production of Gounod's "Romeo et Juliette" at the Kennedy Center's Opera House, that comes as close to the ideal of a balance between music and drama as any production in memory.

The sets, designed by Pasquale Grossi for the Dallas Opera, and David Roberts' elaborate costumes place the action in the context of larger-than-life paintings of Renaissance Verona with all the attention to perspective and light that characterizes the art of that period.

Director Peter Mark Schifter, with gangs of Capulets and Montagues to choreograph, and with swordfights, street scenes and masqued balls to contend with, has everyone on stage participating convincingly and joyfully in the action. Fights rival the old Errol Flynn battles in their rhythm and intensity, and mezzo-soprano Gloria Parker, as Romeo's page Stephano, does a particularly fine job of taunting the Capulets with dancing humor, elegant swordplay and lovely singing.

The cast is remarkably well balanced, both vocally and dramatically. Contralto Gweneth Bean as Gertrude, Juliet's nurse, stands out for the sheer opulence of her singing, but soprano Angela Maria Blasi and tenor Neil Wilson are convincing young lovers. Marcus Haddock and James Busterud are agile and confrontational as the fated Tybalt and Mercutio, and the dukes, counts and friars are properly stately and blind to the implications of their interventions.

Conductor Cal Stewart Kellogg keeps the pace of Gounod's romanticisms blessedly brisk, urging a sometimes reluctant chorus to keep up, and his orchestra is splendid. THE WASHINGTON OPERA --

"Romeo et Juliette." At the Kennedy Center Opera House Friday and Monday, Thursday and November 22 (matinee).