CAMELOT, produced by Mike Merrick and Don Gregory; book and lyrics by Alan Jay Lerner; music by Frederick Loewe; based on "The Once and Future King" by T.H. White; directed by Frank Dunlop; sets and costumes by Desmond Heeley; lighting by Thomas Skelton; musical director Franz Allers; choreography by Buddy Schwab.

With Richard Harris, Meg Bussert, Richard Muenz, Barrie Ingham, James Valentine, Albert Insinnia, William Parry and Thor Fields.

At Wolf Trap through Sept. 7.

The appeal of an elaborate musical like "Camelot," which is having a brief and nearly sold-out run at Wolf Trap Farm Park this week, is rather like that of a formal dinner party. The enjoyment comes not from any cathartic bacchanalia, but from the proper construction of expected elements. Beautiful service, luminous candles and witty companions orchestrated with harmony and care produce an evening that is built on ritual but enriched and enlivened with taste, and in such a manner this production of "Camelot" is a celebration of craftsmanship and excellent components.

Magnificence reigns, magic created by spectacular scenery, extravagant costumes, stirring melodies and wonderful performers. This touring production is, of course, rather formal and pageant-like. The despair of King Arthur, caught in a paradox created by his own goodness, is as touching as Richard Harris can make it, but it is framed by the conventions of a pageant and is thus somehow distant. Just as the display must be large and grand to fill the stage of a huge hall, so the emotions are also writ large and felt from afar.

But "Camelot" does not present itself as anything other than what it seems to be -- a musical extravaganza. Enormous sets designed by Desmond Heely descend and ascend with astounding speed, moving the scene from a forest to a castle to a throne room and so forth with nearcinematic rapidity. When Lancelot appears to rescue the adulterous Guinevere from the stake, beseeched to do so by King Arthur who cannot save her from the verdict his own system of law required, he is moved across the stage on what resembles a vast battlement-like tree. When Nimue, the seductive nymph, entices Merlin away, she appears to be floating high above the stage, trailing cloth to suit a small army.

Camelot was the Alan Jay Lerner-Frederick Loewe musical that followed "My Fair Lady" and the fact that they have a particular style is clearly reflected in both musicals. Some have complained there are too many echoes of the one in the other, but it is not unreasonable to expect great craftsmen to have artistic signatures. One such signature is the talk-song -- songs that are often more effective half-spoken rather than sung. This is lucky for Harris, who talks better than he sings but carries off his numbers well.

He is an athletic Arthur, loping around the stage in the early scenes like a dog recently let out of a kennel. He is at first a petulant king, as befits a man who landed on the throne by accident, as he tells it, because he just happened to see this sword sticking out of this stone and pulled it out. He changes and matures during the show, achieving greatness as a peace-loving king and then finding his "fleeting wisp of glory" torn apart by the combined forces of his evil, illegitimate son, Mordred, and the inevitable love between his best friend Lancelot and his beloved wife Guinevere. It is this emotional journey that makes "Camelot" a bit more than an adventure fairy tale. There is no happy ending, other than the somewhat contrived arrival of a boy who gives Arthur the hope his dreams will live in posterity.

It takes a strong actor not to be swallowed up by such a production and Harris is a confident companion to the scenic magnificence.Fortunately, the producers have not stinted on the performers any more than on the set and costumes. Richard Muenz is a handsome and resonant Lancelot, the man who sings a love song to himself but who later proves able to make good on his pompous playings. Meg Bussert is a simple and appealing Guinevere and her soprano is a pleasure. Barrie Ingham is a special treat as the daffy King Pellinore and Albert Insinnia is a fine, slimy Mordred.