Stevens died Wednesday night at her Manhattan home, said her son, Nicolas Surovy.
Stevens started singing with the Met in 1938, on tour in Philadelphia. Among her greatest roles was the title character in the opera "Carmen," which she sang for 124 performances.
The Met called her "a consummate artist, treasured colleague, and devoted supporter of the company for 75 years."
Stevens knew that the soaring notes and huge themes of opera "was her medium," Surovy said. "She knew it, felt it, lived it."
Always one to chart her own way, Stevens turned down an early chance to sing at New York's Metropolitan Opera when she felt she needed more study in Europe. She turned her back on Hollywood in the 1940s after roles in two successful films because she loved opera so. And in 1961, she retired from performing opera, saying she wanted to bow out when she still had a great voice.
"It always bothered me, these great singers when I heard them again and again, remembering how magnificent they sounded once and no more," she said.
While she largely left performing behind, she remained active behind the scenes as an administrator of a touring opera company and as an educator, helping to foster the growth of opera across the country and the rise of singers trained in the U.
"While I was a young singer, people always talked to us about a golden age of opera," she told the Washington Times in 1990. "Now they tell me that I was part of a golden age. It's all a little ridiculous. We are actually living in a golden age right now, an age of great American voices."
That was the year she was chosen for the Kennedy Center Honors, hailed as a singer "who raised the art of opera in this country to its highest level."
Her earthy portrayal of Carmen brought her particular acclaim in the early '50s, spotlighting her acting as well as her singing.
She recalled that director Tyrone Guthrie "told me, think of your body and nothing else, from the top of your head to your feet."
"I had to learn to move my body and feel like this Spanish woman."
In those pre-PBS days, she made history of a sort in 1952 when her "Carmen" was seen coast to coast—telecast from the Met to more than 30 "television theaters." It was believed to be the largest audience ever to see a single opera performance.
Among her other celebrated roles were Octavian in "Der Rosenkavalier," Orfeo in "Orfeo ed Euridice," Orlovsky in "Die Fledermaus," Cherubino in "The Marriage of Figaro" and Dalila in "Samson et Dalila."
Her brief Hollywood career began in 1941 opposite Nelson Eddy in "The Chocolate Soldier." ("He really could have had an operatic career, but he just made too much money, too soft and too easy," she recalled.)
The success of "The Chocolate Soldier" led to a role in the 1944 Bing Crosby smash "Going My Way," which won several Academy Awards, including best picture.
"I probably would never have reached that vast public had I not done films," she said. "At least, I won a lot of people over to opera."
In the mid-'60s, she was the head of the short-lived Metropolitan Opera National Company, which gave budding singers a chance to tour and gain vital performing experience. The project was abruptly killed after a couple of seasons when Met General Manager Rudolf Bing deemed it too costly.
She said later she wasn't bitter, but "we needed that company, and we need it now. I can see the singers being turned out of the conservatories, good talent, exceptional talent, well trained, but with no chance for experience."
She returned to the task of fostering young talent as president of the Mannes College of Music from 1975 to 1978. "I had a good career," she said. "Now the joy is in watching the young musicians grow, mature, and perhaps become successes."
She was born Rise Steenberg in New York City; her unusual first name, pronounced REE'-zah, came from her Norwegian forebears. "In school, I was called everything but Rise," she once recalled. "I would have arguments with the teachers. I would say, 'I should know how to pronounce my own name.'"
Her mother took her to an audition for a radio children's hour when she was about 10, and her talent was immediately recognized. "I didn't know what was happening, but sure enough they took me and put me on the air."
During her four years on the show, she even learned some opera melodies. "It never registered with me; I didn't know anything about opera, but I was singing it."
A leading voice teacher, Anna Schoen-Rene, heard her in a little theater opera production when she was 16, and that led to scholarship study at the Juilliard School, and later, study in Europe.
She made her professional opera debut in Prague, and it was there she met her husband of more than a half-century, actor Walter Surovy. Nicolas Surovy was their only child.
She is also survived by her granddaughter. Surovy says no funeral will be held, but a private memorial is planned.