The East Garden Court was packed last night for a handsome concert by the National Gallery Orchestra under Richard Bales' direction. Bringing to a close the 36th Amercian music festival, the program offered a lively mix of music from this nation's past and present.

Few, if any, of the composers represented were familiar. The opening work was an overture by Charles Hommann who, according to Bales, is a mystery man in American music. Little is known except that he was active around Philadelphia and wrote music for several Moravian communities. His appealing overture in D major, written about 1840, was like the first movement of a Haydn symphony, complete with an introduction in the minor key.

The overture was followed by "Dance for Orchestra," written in 1978 by Anna Larson, who lives in the Washington area. The work centered about contrasts between passages of rhythmic emphasis and flowing, lyrical sections. The basic material was interesting and the orchestra was deftly handled but the integration of the disparate elements was not a total success. The broad cadence of the close, lovely though it was, came as something of a surprise.

There was a stimulating jump from the lyricism of Larson to the strident, asymetrical rhythms of Joseph Ott, who is currently composer-in-residence at Emporia State University in Kansas. Based on a three-note motif, his work, "Palo Duro," derived most of its impact from a single device, the orchestral crescendo, which occurred over and over again. The effect was impressive but after a few such climaxes, one wanted to see something else happen, either a shift in mood or a different working out of the material.

The closing work, written in 1948, was "Symphony No. 3" by Gardner Read, who recently retired after 30 years of teaching at Boston University. An intense and effective work, the symphony made inventive use of contrapuntal forms and techniques of the past