With a career spanning an incredible half century, from the late ‘40s until the early ‘90s, German dramatic mezzo-soprano Christa Ludwig tackled some of classical music's most demanding roles with an ease and beauty that made hers an essential voice. Ludwig easily cut through massive orchestras (Verdi's Messa da Requiem, Wagner's Tristan und Isolde), but she also commanded intensely intimate, delicate moments (Mozart's “Soave sia il vento” from Cosi fan tutte, Schubert's “Ave Maria”). When on stage, she was a pure gravitational force—case in point: Mahler's “Resurrection” Symphony.