Following Sir Rudolf Bing's departure as director, Sills finally made her debut at the Metropolitan Opera on April 7, 1975 in "The Siege of Corinth", receiving an eighteen-minute ovation before singing a note. Other operas she sang at the Met include "La Traviata", "Lucia di Lammermoor", "Thaïs", and "Don Pasquale" (directed by John Dexter). In an interview after his retirement, Bing stated that his refusal to use Sills – as well as his preference for engaging, almost exclusively, Italian stars such as Renata Tebaldi due to his notion that American audiences expected to see Italian stars – was the single biggest mistake of his career. Sills attempted to downplay her animosity towards Bing while she was still singing, and even in her two autobiographies. But in a 1997 interview, Sills spoke her mind plainly, "Oh, Mr. Bing is an ass. hile everybody said what a great administrator he was and a great this, Mr. Bing was just an improbable, impossible General Manager of the Metropolitan Opera... The arrogance of that man."