Renata Tebaldi (US: tə-BAHL-dee, Italian: [reˈnaːta teˈbaldi]; 1 February 1922 – 19 December 2004) was an Italian lirico-spinto soprano popular in the post-war period, and especially prominent as one of the stars of La Scala, San Carlo and, especially, the Metropolitan Opera. Often considered among the great opera singers of the 20th century, she focused primarily on the verismo roles of the lyric and dramatic repertoires. Italian conductor Arturo Toscanini called her voice "la voce d'angelo" ("the voice of an angel"), and La Scala music director Riccardo Muti called her "one of the greatest performers with one of the most extraordinary voices in the field of opera."
Source : Wikipedia