Neil Simon's relentless fertility is a real esthetic virtue. Clearly he can write a play about anything: it would be fun to set him up officially as America's playwright laureate, perhaps in the theater on Broadway that he owns, where he could create a continuous theatrical obbligato to the events of the day, dashing off a play on Billy Carter, or Lee Marvin's nonmarital problem or even a fast funny musical about the OPEC countries. And on the side he could run a more private service, whipping out personalized plays for ordinary people, say a one-acter on your kid's bar mitzvah or a gag epithalamium on your impending marriage. Something like this is what Simon has done in "They're Playing Our Song," apparently based on the real-life relationship between composer Marvin Hamlisch and lyricist Carole Bayer Sager, and which includes songs by Marvin Hamlisch and Carole Bayer Sager. I enjoyed it.

This kind of thing is Neil Simon at his best. He's grasped the essential truth about life today—that no matter how serious the details may be, it's a joke, Mac, a series of routines turned out by the Great Gag Writer in the Sky. When the President of the United States makes a crack about "Montezuma's Revenge" to the President of Mexico, you know we've reached the moment in history when everyone wants to be a stand-up comic. In Simon's world, everyone is. His hero, Vernon Gersch …, is a neurotic, arrogant but lovable writer of hit tunes, and his heroine, Sonia Walsk …, is a neurotic, vulnerable but lovable writer of hit lyrics. They come together to collaborate on some songs, and their musical chords lead to romantic discords, the cutest upsy-downsy romance played out in a rippling rhythm of thirteen scenes, 173 gags and nine songs.

It's an unassuming but stylish piece of work, amiable, amusing, warm, winning and like that. And in its own quiet way it's something of a breakthrough in Broadway's current musical dilemma, whose horns are the zillion-dollar extravaganza like "Ballroom" and the pocket-size, "bookless" musical like "Ain't Misbehavin'," "They're Playing Our Song" steps intelligently in between these extremes.