Six members of the Bennington Ensemble, a group of musicians who teach at Bennington College, presented a concert in Paine Hall Friday night. The music was uniformly excellent; the musicians were not.

Rameau's Troisieme Concert opened the program. This is fragile stuff--even the rolicking tambourins that come at the end lose all their effectiveness if not played with the utmost delicacy. The performances by violinist Orrea Pernel, cellist George Finckel, and pianist Claude Frank were decidedly unidiomatic. Their tone was harsh, their phrasing stiff, and their technique heavy-handed.

Leslie Chabay cleared the air with his luminous renditions of six German songs. Expertly accompanied by Mr. Frank, he sang these settings of Goethe poems with warmth and clarity.

Lionel Nowak's Trio for Clarinet, Violin, and Cello provided the evening's novelty. Nowak, who also teaches at Bennington, uses a lively semi-atonal style that is immediately appealing without being banal. The unique combination of instruments creates unusual timbre effects, and the performance (except for some excessive violin scraping) did the work full justice.

The versatile Mr. Chabay returned to sing Bartok arrangements of five Hungarian folk songs. These range from the pathetic irony of In Jail to the half-cheerfulness of Dance Song, and the tenor sung them all with such finesse and sympathy that he was called back for an encore.

Mozart's G Minor Piano Quartet, one of the real gems of the chamber repertoire, received a performance that can most mercifully be described as undistinguished. Not only was the technique (especially of violist Joseph Schaaf) inadequate, but also the conception of the music seemed stilted. Instead of employing the straightforward, relaxed interpretation that the work calls for, the ensemble tried to make it sound like a Nineteenth Century virtuoso piece. They failed.