Franz Welser-Möst opens his 25th and final season as Music Director of The Cleveland Orchestra with two 20th-century masterpieces. South African soprano Golda Schultz lends her radiant voice to Richard Strauss’s staggeringly beautiful Four Last Songs, written in the sunset of the composer’s life. Complementing this, Shostakovich’s Eighth Symphony moves from despair to resilience with the composer’s characteristic mix of biting wit and veiled criticism.