At 94, the San Francisco Symphony’s former music director Herbert Blomstedt returns for an evening of indelible Beethoven and “inextinguishable” Carl Nielsen. Yes, that’s the official title of the great Dane’s Symphony No. 4. Make this concert a priority. As everyone knows, the devout and gentle American-born Swedish maestro is operating in a singular state of grace, even by his own exalted standard. —M.G.