Michael Tilson Thomas and the San Francisco Symphony perform Wagner’s lush Siegfried Idyll. Originally a birthday gift for Wagner’s wife, Cosima, its premiere took place on the morning of her birthday as she awoke to the sounds of a small chamber orchestra playing on the staircase leader to her bedroom. With pastoral scenes, bird songs, horn calls, and delicate melodies, listen to this moving music on the San Francisco Symphony’s2019–20 Digital Concert Series.