William S. Gilbert supplied the mots justes for one's reaction to the production of his (and Sir Arthur Sullivan's) "The Mikado" playing tonight and tomorrow night in the F. Scott Fitzgerald Theater at Rockville Civic Center. The words are "modified rapture."

"The Mikado" is a resilient piece of theater; it has survived triumphantly through such adaptations as the "Hot Mikado," and it thrives in amateur productions. It worked well last weekend in the first round of performances by the Victorian Lyric Opera Company despite rudimentary scenery, costumes that did not always fit well, a leading soprano with laryngitis and an individuality of performing styles that contrasted sharply with the ensemble approach cultivated by the late D'Oyly Carte Company.

This "Mikado" boasts a Pooh-Bah (astrophysicist James E. Felton) who sometimes calls the late Boris Karloff to mind, a Mikado (Michael Consoli) who has sung with a number of opera companies and who seems ideal for the role of the Pooh-Bah, an appealing Nanki-Poo (Robert Kimball) and a Yum-Yum (Amanda Raphaelson) who acted the part well while soprano Linda Kirk, singing on the sidelines, compensated for her temporarily missing voice. Daniel Lyons, as Ko-Ko, is younger than the performers one usually sees in this role; his interpretation was rather nontraditional but vivid and satisfying.

Those who hunger for a "Mikado" priced far below the going rate for Gilbert and Sullivan at the Kennedy Center may try this one with a fair expectation of enjoyment if they go with realistic expectations. And those (more numerous than you might think) who treasure the amateur spirit above slick professionalism in such efforts will be delighted.