Nicolai Ghiaurov (13 September 1929–2 June 2004) was a Bulgarian opera singer and probably the most famous bass of the postwar period. He was admired for his powerful, sumptuous voice, and was particularly associated with roles of Verdi. Ghiaurov was married to the Italian soprano Mirella Freni, with whom he frequently performed. Ghiaurov made his Metropolitan Opera debut in 1965 as Mephistopheles. He sang a total of eighty-one performances in ten roles there, last appearing there in 1996, as Sparafucile in Rigoletto. During the course of his career, he also performed at Moscow's Bolshoi Theatre, the Vienna State Opera, and Covent Garden.