The Tokyo String Quartet opened the Corcoran Gallery's distinguished chamber music series last night. They were joined by violist Raphael Hillyer for performances of the Mozart B-Flat Major Viola Quintet and the Brahms G-Major Quintet, Op. 111, and they began the evening with a disciplined reading of the Haydn G-Major Quartet, Op. 77, No. 1.

The Corcoran's bright acoustics are not always kind to the Tokyo ensemble whose preferred hallmark is a well-groomed and homogeneous sound. But in this instance there were some pleasant benefits from the acoustical spotlighting effect. The Corcoran's superb set of Amati instruments, which are on loan to members of the Tokyo quartet, could be heard individually with unaccustomed clarity. The warmth of the viola and the smooth matching of the two violins became, at times, the focus of the ensemble, and, while the music itself took a back seat during these moments, the glories of the instruments were well worth the trade off.

The quartet's great strengths were constantly in evidence, however, in the deliberate control of the opening Haydn tempos, in the sleek unisons of the Mozart adagio, in the seamless dialogues of the Mozart finale and in the intense concentration of the Brahms second movement, where every vibrato and subtlety of phrasing was carefully measured and thoughtfully delivered.

Spontaneity, on the other hand, is not the Tokyo quartet's forte, and where this sort of release was called for, in the Haydn finale and in the first movement of the Brahms, the effect was more of frantic activity than of driving energy. But even here, their balance and intelligence kept the music interesting.