A PARTRIDGE IN A PEAR TREE -- In the Eisenhower Theater at the Kennedy Center through February 1.

"Is it any good?" the critic's friends and relations always ask cagily, before agreeing to go to an opening-night performance. No one seems to wonder why, if the question could be answered then, the critic need attend at all. But the first thing one learns in that trade is how many plays "sound" wonderful and aren't, and vice versa.

However, if anything can be said to "sound" awful from the ingredients, it's a play with a film star who is out of practice on the stage, but, being considered able to fill the theaters on name alone, chooses something for personal convenience, such a play with a role for the less famous spouse so they can travel together. And while the theater is full of surprises, "A Partridge in a Pear Tree" starring James Mason and his wife, Clarissa Kaye, lives down to that expectation.

The play, by Leslie Stevens, is a sort of "Trial by Jury," if Gilbert and Sullivan had written that without music or wit. Mason, in a judge's robe and wig, leans leeringly toward the truculent but supposedly golden-hearted Kaye in the witness box, and all concerned prattle continually about the rewards of perjury and fraud. Stripped of its satire -- delivered, instead, with a smug, moral tone -- the argument that it is laudably humanistic to ignore the ethics of the legal profession to clear one's name is -- well, rather offensive.

For the opening night performance, at the Kennedy Center, the play had been cut 40 minutes, but it was still continually repetitive, with line after line making the same few statements. But one could not tell whether this, like the inconsistencies in plot details, was the playwright's fault, or that of the actors who, not knowing the lines, may have been repeating themselves because they were lost.

The staging, too, was repetitive. Nearly all of the play takes place in the judge's chambers, and the characters come on stage and off as he summons them, one by one, though a guard, after which a prison matron slowly shuts the big doors. Minor characters have one gimmick each -- one blubbers, another jumps -- that they keep on doing.

The best thing that can be said about this is that it does capture a court atmostphere of hammering away at the same unpleasantness, over and over again.