Michael Tilson Thomas, the celebrated American conductor and composer, died at 81 after a years-long battle with brain cancer. He founded the New World Symphony in Miami Beach in 1987 and led the San Francisco Symphony as music director from 1995 to 2020. Tilson Thomas championed Gustav Mahler and American composers, produced acclaimed recordings, and created the PBS and multimedia education project Keeping Score. His innovative programming, recordings and education initiatives reshaped American classical music and brought new listeners into the concert hall.