SF Symphony Music Director Laureate Michael Tilson Thomas, Courtesy: SF Symphony.

San Francisco Symphony Music Director Laureate Michael Tilson Thomas underwent an emergency surgery to remove a diagnosed brain tumor, the symphony announced on Friday. The tumor was diagnosed after a series of tests. The procedure was done at UCSF Medical Center in San Francisco and was successful. His recovery is expected to take several months.

As such, the symphony has canceled his public appearances through October. Michael Tilson Thomas has also has also canceled his engagements with the National Symphony Orchestra for the Kennedy Center’s 50th Anniversary, the Indianapolis Symphony Orchestra, the New World Symphony and the Chicago Symphony Orchestra.

“I deeply regret missing projects that I was greatly anticipating,” Tilson Thomas said in a news release. “I look forward to seeing everyone again in November.”

Tilson Thomas is being cared for doctors at UCSF, who are continuing to explore his treatment options. He stepped down as music director of the symphony in 2020, after decades at the helm.