It is almost as much of an art to construct a program of contemporary music as it is to play the music itself. Stephen Robert Kleiman and the New World Players, who completed their first session at the National Academy of Sciences last night, seem to have given this a good deal of thought.

The concert opened with a Theme and Variations by Stearns that was intellectually polyphonic, understated and a gentle limbering-up execise for the audience. The tough stuff followed: Schwantner's "In Aeternum-Consortium IV," "Conversations" by Kurtz and Tower's "Breakfast Rhythms I and II." As a reward to the audience for working so hard, the concert ended with "Dans le Sable" by Rush, a stage piece for soprano, narrator, altos and instruments, dedicated to immobility.

The more challenging part of the program also brought its own rewards, however. Schwanter, who won a Pulitzer Prize in 1979, has a marvelous ear for unusual sounds. "In Aeternum-Consortium IV" is for solo cello and a small group of instrumentalists who, at times, are called upon to use their bows on bells and other unlikely, but intriguingly responsive, intruments.

Kurtz's "Conversations" comes with a story line -- the development and eventual disintegration of conversation at a social event. The music is dependent on this program and cannot really stand alone, but, on its own terms, it is witty and well put together.

Tower's piece, for clarinet and five instruments, is intricately structured but highly logical. The relationship between solo and ensemble is a cooperative one, and the idiom, while complicated, is essentially conservative. c