THEY'RE PLAYING OUR SONG -- At the National Theater through February 21.

When the curtain goes up on a Neil Simon play to reveal one of those expensively tacky living rooms inhabited by a writer who can't cope with the ordinary problems of life, we all know what to expect: wall-to-wall wisecracks.

But the humor in "They're Playing Our Song," now at the National Theater, is more like cut-your-own shag bathroom carpeting -- it covers the territory, in a lumpy sort of way, but only to fill in around the obvious.

This is a road-show company of a budget musical -- two people blaring into their body microphones trying to fill the theater with noisy fun. For every unexpected line, there a dozen predictable ones: "Our relationship could stand a little more work," "I've got big trouble in that area," "We should get to know each other," "I feel the need to talk it out," "What is it you're so afraid to find out about yourself?" and "God, you are so straight."

One is asked to believe that the young woman who utters this phychobabble is infuriatingly original to a conventionally successful young man. If you ask yourself why he needs to learn to cope with such a person, you will have a dreamy time of it.

Marsha Skaggs lends the part of the heroine, created by Lucie Arnaz, quite a bit of peppiness: Victor Garber, somewhat less charm to the hero.