Fo ra few minutes during the Bach Society Orchestra's concert Saturday night, it was difficult to remember that a chamber orchestra was playing in Paine Hall. The sonorous climaxes of three songs from Hindemith's "Marienleben" sounded forth with all the intensity and power of a full symphony. Disregarding the question of propriety, it was an astonishing demonstration of the virtuosity of the orchestra and its conductor, Michael Senturia.

The soloist, Jean Lunn, realized fully all the expressive and emotional possibilities of these songs. Her voice, although not a big one, is suited to the demands of this kind of music. The performance was properly dramatic, the last song, "Geburt Christi," being particularly exciting.

Mozart's motet for soloist and orchestra, "Exsultate, jubilate," which preceded the Hindemith, fared less well. The spirit of Hindemith hovered over, giving an air of tenseness that was out of key with this more gentle work. The orchestra, which is usually excellent in accompaniment, was strangely insensitive and much too loud. Miss Lunn, although technically in full command of her difficult part, had to push her voice, and still was often inaudible, especially in the cadences. The entire performance of this work bordered on the hysterical.

For three movements of Haydn's Symphony No. 2 in B-flat, the last work performed, the orchestra sounded as though it had not yet calmed down after the Hindemith. The balances were poor and the tone in general ragged. Mr. Senturia held the group together with difficulty, and the attacks were consistently bad. The second movement failed to sing, and the menuetto did not have the grace and style which is usually the Orchestra's strongest point.

Then, miraculously, the finale emerged as if it belonged to a different piece. The orchestra played in true chamber fashion, always together, with ease and spirit. The loose ends were gathered in, and the tone regained its customary clarity. The coda, in Haydn's most humorous vein, added just the right amount of playfulness to a sparkling performance. Even after the disappointments of the first movements, this was worth waiting for.

The concert opened with a vigorous performance of Vivaldi's Concerto Grosso for four solo violins. David Hurwitz, Ronald Hathaway, Katherine Gratwick, and Ruth Miller performed the solo parts with consistent vitality and precision, if not perfect intonation. Although the contrast between the ensemble and the concertino group was not as great as it might have been in a larger orchestra, the string section demonstrated once again its brilliance and fullness, while Mr. Senturia emphasized the formal power and relentlessness of the concerto.