The National Theatre will have a hit on its hands for the rest of December; the loudness and length of applause "The Music of Andrew Lloyd Webber" has been getting leave no doubt of that. And perhaps this is as it should be.

Lloyd Webber is a skilled theatrical composer (a skilled orchestral and ecclesiastical composer too, as a matter of fact), the evening's songs are carefully selected for continuity and contrast, and a capable roster of singers has been assembled for this touring company. Some singers are of operatic quality; others have the vitality and acting ability of seasoned Broadway performers. Still, I can imagine getting even more enjoyment out of an evening of "The Music of Stephen Sondheim" or "The Music of Cole Porter."

This show is not problem-free, but it is a good evening of varied entertainment, from Ray Walker's rock mannerisms in "Jesus Christ Superstar" excerpts to Brigid Brady's bel canto singing in "The Phantom of the Opera." Some numbers are done as well as I ever expect to see them performed.

Laurie Stephenson in "Don't Cry for Me Argentina" not only has the right voice, makeup and costume (somewhere between a senior prom gown and a wedding dress) for Evita Peron making political-erotic overtures to an entire nation, she also has exactly calculated the stiff, mechanical gestures to convey Evita's blend of nervousness and insincerity.

Kelli James brings a special wistfulness to "I Don't Know How to Love Him" and "Everything's Alright" from "Jesus Christ Superstar" and "Memory" from "Cats." There is a charming sweetness in Lindsay Dyett's performance of "Unexpected Song" from "Song and Dance." Connie Kunkle finds the dramatic core of "Take That Look Off Your Face" from "Song and Dance," as Laurie Williamson does for the rejected mistress's song "Another Suitcase in Another Hall" from "Evita." Walker Keeling swaggers well and does an impressive midair cartwheel in "Mr. Mistoffelees" from "Cats," and D. Michael Heath makes a memorable moment of "The Music of the Night" from "The Phantom."

Best of all is the touching, funny and beautiful portrayal of "Gus: The Theatre Cat" by Kunkle and Rufus Bonds Jr., a performance that conceals real depth beneath its perfectly conceived surface. In the special success of this item lies a key to one of the show's problems. "Gus," one of the quieter episodes in the vigorously episodic "Cats," has and needs no dramatic context; it is a miniature masterpiece complete in itself.

Almost everything else in this show is ripped out of a carefully constructed totality, and the introductions supplied before the singing begins don't begin to provide everything you need for full enjoyment. "Don't Cry for Me Argentina" takes on its full meaning only in the context of "Evita." Without that context, you don't understand the meaning of Stephenson's robotlike gestures and you may dismiss a finely nuanced performance as clumsy. Because it lacks contexts, this show left me wanting to see "Jesus Christ Superstar," "Joseph and the Amazing Technicolor Dreamcoat" and "Evita" again. Could this be intentional?

Another weakness is the fact that, with occasional exceptions, the women in the show noticeably outshine the men.

Finally, in a theater as small as the National, it is absurd to see an orchestra of more than 30 pieces heavily miked and amplified. That might be necessary at Capital Centre, but why should an audience in the National have to settle for sound of Capital Centre quality? The producers should take a chance and let the orchestra's natural sound be heard. It will not be worse than what is being heard now.

Some of the singers may need mikes; others obviously don't, but no doubt if one is miked all have to be. But hand-held mikes, which may be okay for rock concerts, do not belong in a show like this. Some numbers were sung in front of mikes on stands with much better results. Not only was the sound quality improved, but you could see the singer's entire face, and both hands were free to gesture -- more expressively and with much better balance than the usual one-arm-waving style.

The best moment of the show, at least on Wednesday night, came in the "Pie Jesu" from "Requiem" when Laurie Williamson stepped back (on purpose?) a little too far from the microphone and her natural voice came across the footlights. Not only did it sound much better than her amplified voice, but it was comforting, for a moment, not to hear the voice coming from a speaker on your right while you saw the singer singing on your left.

The Music of Andrew Lloyd Webber, supervised by Andrew Lloyd Webber. Conductor, Vincent Fanuele. With Eric Bennyhoff, Rufus Bonds Jr., Brigid Brady, Nat Chandler, Lindsay Dyett, D. Michael Heath, Kelli James, Walker Keeling, Connie Kunkle, Laurie Stephenson, Ray Walker and Laurie Williamson. At the National Theatre through Dec. 31.