Despite her major stage career lasting barely a decade in the 1950s and ’60s, soprano Maria Callas left an indelible impression on the operatic world. Onstage, she was a magnetic presence; in the studio, her roles proved as engaging dramatically as they were vocally. She possessed the most incredible instrument: a voice with almost infinite dynamic range that was, nevertheless, always at the service of the music. Her Leonora from Verdi’s Il trovatore, one of the composer’s most demanding operas, quickly became one of Callas’ iconic roles. This 1956 recording with Herbert von Karajan and the Orchestra and Chorus of La Scala, Milan, proves why. Callas’ poignant Act 4 duet with tenor Giuseppe di Stefano (as the troubadour Manrico) is a vivid example of the matchless purity and intensity of her voice, while her vocal control in the Act 1 solo “Tacea la notte placida” (“The peaceful night lay silent”) is breathtaking.