Yet Ms. Scotto’s combination of talent and hard work drew admiration from fellow singers. “She’s unique in vocal coloration,” the baritone Sherrill Milnes told The New York Times Magazine. “Even if you don’t understand the language, you feel it. She will also sacrifice vocal beauty to get the word or the emotional intention across.”

Renata Scotto was born in humble circumstances on Feb. 24, 1934, in Savona, then a small Italian fishing town on the Mediterranean coast west of Genoa. Her father, Giuseppe, was a police officer and her mother, Santina, a seamstress. When Savona came under Allied bombardment during World War II, Renata, her older sister Luciana and their mother took refuge in a nearby Alpine village, Tovo San Giacomo.

Even as a child, she showed signs of the diva to come. In Tovo San Giacomo, she would stand by her bedroom window and regale passers-by with the latest songs favored by the leading Italian tenor, Beniamino Gigli. The villagers applauded and often tossed her candy. “You see, I never sang for nothing in my life,” she noted in her 1984 memoir, “Scotto: More Than a Diva,” co-written with Octavio Roca.

When she was 12, Renata was invited by an uncle to her first opera — Verdi’s “Rigoletto,” with Tito Gobbi in the title role — at the Teatro Chiabrera in Savona. “Gobbi the great singer and Gobbi the great actor made me decide that night that I would be an opera singer,” she recalled.

As a teenager, Ms. Scotto was sent to Milan for voice and piano lessons. The only lodging her family could afford was at a Canossian convent, which she described as “somewhere between a jail and a very austere kindergarten.” The mother superior lectured her on the banality of secular music and a nun tried to steal her music scores. But outside the convent, her teachers, especially the soprano Mafalda Favero, recognized her talent and helped bring about her career. Several years later, she studied with the Spanish former soprano Mercedes Llopart — “who really taught me how to sing,” Ms. Scotto said.