The music on last night's 20th Century Consort program at the Hirshhorn Museum provided a marvelous overview of the myriad ways that content and technique can be manipulated.

So far in this century, Bartok is the master of the integration of these musicial elements, and his Quartet No. 5 is perhaps the supreme example of this art. Its thematic material is a microcosm of its architectural structure, and like a holograph, each small section is a reflection of the whole.The Emerson Quartet, whose members are part of the larger Consort, projected this structural unity and coherence with power and conviction in a splendid performance.

In "A Poison Tree" by Richard Wernick for soprano and chamber ensemble on the Blake poem, the content of the musical material was of primary interest. A well-thought-out framework was always evident, and its technical vocabulary was nicely and modestly handled, but one was more interested in what was going on than in how. Just the opposite was true of Maurice Wright's "Holding Together," an aptly named piece for amplified piano and tape, skillfully played by Lambert Orkis. Here the interrelationships of the instruments (if the synthesizer can be so considered), the metamorphosis of the piano into something that sounded mechanical, and the virtuosic control of the media were always in the foreground.

The concert ended on a nonintellectual note, with Berio's lovely folksong settings, sung by Lucy Shelton with great beauty.