JTA — One year ago, Michael Tilson Thomas lifted his baton to conduct a concert in San Francisco that he said would be his last . The scion of Yiddish theater and luminary of contemporary classical music had been diagnosed with a recurrence of brain cancer, and he knew his days were numbered. “We all get to say the old show business expression, ‘It’s a wrap,’” he said on his website after conducting Gustav Mahler’s Symphony No. 5 with the San Francisco Symphony, one of several orchestras he led during his storied career. He signed off: “Life is precious.” Thomas died Wednesday at his home in San Francisco, four days short of the one-year anniversary of that concert. He was 81. Among the many paying tribute to Thomas were those whose appreciation stretched back through his long career to his family roots in the thriving Yiddish theater scene of early 20th-century America.…