“San Francisco Symphony patrons who watch the stage of Davies Symphony Hall carefully are seeing a welcome sight this month. William Bennett, the orchestra’s principal oboist, is back in action after a bout of tonsil cancer. Bennett was diagnosed in September, just before Music Director Michael Tilson Thomas and the orchestra made their live recording of Mahler’s Ninth Symphony. He kept mum until the recording sessions were over, not wanting to distract anyone from the task at hand, then went in for surgery followed by a punishing course of radiation and chemotherapy. Today, the tumors are gone, and Bennett, 49, is back where he belongs.”