Joel Lazar '61 and the Bach Society Orchestra started off their season brilliantly yesterday evening at Sanders Theatre. An unusually large crowd listened raptly as the orchestra handled piece after piece with enthusiasm and exemplary technical mastery. It is quite clear from this showing that Mr. Lazar has been more than an excellent trainer for the group. He has also been a near inspirational leader.

His clear grasp of the crispness requisite for a Mozart overture was in evidence as the orchestra performed the overture to La Clemenza di Tito with note-perfect accuracy while preserving considerable nuance in phrasing. The sutleties never detracted from the urgency and vitality of the piece--Which, by the way, is a curious amalgam of Gluckian melodrama and a Rossinian Flippancy, a flippancy that the Italian himself rarely could equal.

As accompanists, Mr. Lazar and the Bach Society were perhaps even more impressive. Throughout the performance of Mozart's Clarinet Concerto in A, the orchestra distinguished itself for its bright string tone, its fluid phrasing and the rapport it enjoyed with the soloist, Andrew Schenck '62. Mr. Schenck, who obviously has complete control of the clarinet, achieved a beautiful, rich tone while effortlessly hurdling the technical obstacles which pepper the piece.

It was a bit disappoint to see the Bach Society let down its patron saint after serving his successor so handsomely. An ensemble of ten strings, supported by Michel Singher '62 on the harpsichord, was foiled by the virtuosic demands of the Great Man's Brandenburg Concerto No. 3. Intonation was faulty throughout, if not in the 'celli, than in the violins; the resultant thick texture took the edge off of Mr. Lazar's intimate and a bit over-respectful interpretation.

But after the first minute of Piston's Serenata for Orchestra, one realized that everything was completely under control again. Professor Piston's work of 1956 was originally commissioned by the Louisville Symphony and received a fittingly excellent performance at its East Coast premiere last night. After being delighted by its boyish allegro--which has more than a bit of Copland to it--and its sensuous slow movement, I cannot quite understand the reticence of other orchestras to take up the short, light work. Everything that was first rate about the Bach Society's handling of the other pieces on the program was evident here in even greater abundance. Their marvellous tone, perfect, balance and phrasing, and rhythmic and technical assurance all gave Professor Piston reason to beam while he bowed with Mr. Lazar at the Serenata's conclusion.