David Atherton’s farewell concert as Music Director of the Mainly Mozart Festival Saturday offered high spirits, pristine music making, and a touch of valedictory symbolism. At age 69 the intrepid British conductor is stepping down from his festival post, at the top of his form, to give someone else a chance to interpret this repertory. The program included Mozart’s First Symphony in E-flat Major, K. 16, his Symphony No. 41 in C Major (“Jupiter”), K. 551, and Dmitri Shostakovich’s Second Piano Concerto with Adam Neiman.

Thursday at the Balboa Theatre, the Mainly Mozart festival orchestra under Music Director David Atherton’s precise baton flaunted its refined, buoyant sonority as well as its interpretive finesse and masterful unity of execution in a varied program of Mozart, Schubert, Fauré and Poulenc.