Eight months after conducting the city’s ensembles in a charity concert in aid of earthquake victims and survivors in Japan, Christoph von Dohnányi returned to Zürich and conducted the Tonhalle Orchestra in Bartók’s Music for Strings, Percussion and Celesta, as he had done had 11 years earlier. On this occasion the second half was taken up with an even more revolutionary work: Mahler’s First Symphony, which opens with an unprecedented, shimmering A spread across seven octaves of the orchestra, like a rite of spring from 1888.