The unforgettable season at New World Symphony concludes with a performance of Richard Wagner’s profoundly beautiful Siegfried Idyll. Brimming with lush melodies borrowed from his own operas, the work is a musical love letter to his wife Cosima. Matthias Pintscher leads the U.S. premiere of Nina Šenk’s meditative brass trio, and works by Classical contemporaries (and rivals) Wolfgang Amadeus Mozart and Joseph Bologne, Chevalier de Saint-Georges.