Leonard Warren (April 21, 1911 – March 4, 1960) was an American opera singer. A baritone, he was a leading artist for many years with the Metropolitan Opera in New York.

Born Leonard Warenoff in New York to Russian Jewish immigrant parents, Warren was first employed in his father's fur business. In 1935, he joined the chorus at Radio City Music Hall. In 1938, he entered the Metropolitan Opera Auditions of the Air. Despite the fact Warren was obviously a novice, his natural gifts were apparent, and he was immediately given a contract. The Met sent him to Italy that summer with a stipend to study.

Returning to America, Warren made his concert debut at the Metropolitan Opera in excerpts from La traviata and Pagliacci during a concert in New York in November 1938. His formal operatic debut took place there in January 1939, when he sang Paolo in Simon Boccanegra. A recording contract with RCA Victor soon followed.

Warren later sang in San Francisco, Chicago, Mexico City, and Buenos Aires, he appeared at La Scala in Milan in 1953, and in 1958, he made a highly successful tour of the Soviet Union, but for most of his career he remained in New York and sang at the Met. Sometime during that period, he converted to Roman Catholicism, the faith of his wife Agatha, and became extremely devout.

Eleanor Steber (July 17, 1914 – October 3, 1990) was an American operatic soprano. Steber is noted as one of the first major opera stars to have achieved the highest success with training and a career based in the United States.

Eleanor Steber was born in Wheeling, West Virginia on July 17, 1914. She was the daughter of William Charles Steber, Sr. (1888–1966) and Ida Amelia (née Nolte) Steber (1885–1985). She had two younger siblings – William Charles Steber, Jr. (1917–2002) and Lucile Steber Leslie (1918–1999). She made her debut at the Metropolitan Opera in 1940 and was one of its leading artists through 1961. She was known for her large, flexible silvery voice, particularly in the high-lying soprano roles of Richard Strauss. She was equally well-known for her lyrical portrayals of Mozart's heroines, many in collaboration with conductor Bruno Walter. Beyond Mozart and Strauss her repertoire was quite varied. She was noted for success in the music of Wagner, Alban Berg, Giacomo Puccini and also in French opera. Steber sang the lead in the world premiere of the American opera Vanessa by Samuel Barber. She was also featured in a number of Metropolitan Opera premieres, including Strauss's Arabella, Mozart's Die Entführung aus dem Serail, and Berg's Wozzeck.

Marian Anderson (February 27, 1897 – April 8, 1993) was an African-American contralto and one of the most celebrated singers of the twentieth century. Music critic Alan Blyth said "Her voice was a rich, vibrant contralto of intrinsic beauty." Most of her singing career was spent performing in concert and recital in major music venues and with famous orchestras throughout the United States and Europe between 1925 and 1965. Although offered roles with many important European opera companies, Anderson declined, as she had no training in acting. She preferred to perform in concert and recital only. She did, however, perform opera arias within her concerts and recitals. She made many recordings that reflected her broad performance repertoire of everything from concert literature to lieder to opera to traditional American songs and spirituals.

Anderson became an important figure in the struggle for black artists to overcome racial prejudice in the United States during the mid-twentieth century. In 1939, the Daughters of the American Revolution (DAR) refused permission for Anderson to sing to an integrated audience in Constitution Hall. The incident placed Anderson into the spotlight of the international community on a level unusual for a classical musician. With the aid of First Lady Eleanor Roosevelt and her husband Franklin D. Roosevelt, Anderson performed a critically acclaimed open-air concert on Easter Sunday, April 9, 1939, on the steps of the Lincoln Memorial in Washington, D.C. She sang before a crowd of more than 75,000 people and a radio audience in the millions. Anderson continued to break barriers for black artists in the United States, becoming the first black person, American or otherwise, to perform at the Metropolitan Opera in New York City on January 7, 1955. Her performance as Ulrica in Giuseppe Verdi's Un ballo in maschera at the Met was the only time she sang an opera role on stage.

Mario Del Monaco (July 27, 1915 – October 16, 1982) was an Italian tenor who is regarded as one of the greatest dramatic tenors of the 20th century.

Del Monaco was born in Florence to a musical upper-class family. As a young boy he studied the violin but had a passion for singing. He graduated from the Rossini Conservatory at Pesaro, where he first met and sang with Renata Tebaldi, with whom he would form something of an operatic dream team of the 1950s. His early mentors as a singer included Arturo Melocchi, his teacher at Pesaro, and Maestro Raffaelli, who recognized his talent and helped launch his career.

That career began in earnest with Del Monaco's debut on December 31, 1940, as Pinkerton at the Puccini Theater in Milan. (His initial appearance in an opera had occurred the previous year, however, in Mascagni's Cavalleria rusticana in Pesaro.) He sang in Italy during the Second World War and married, in 1941, Rina Filipini. In 1946, he appeared at London's Royal Opera House, Covent Garden, for the first time. During the ensuing years he became famous not only in London but also across the operatic world for his powerful, metallic voice. It was almost heldentenor-like in scope but Del Monaco was no Wagnerian, confining his activities overwhelmingly to the Italian repertoire.

Renata Tebaldi (Pesaro, Italy, 1 February 1922 – San Marino, 19 December 2004) was an Italian lirico-spinto soprano popular in the post-war period. Acclaimed as one of the most beloved opera singers of all time, she primarily focused on the verismo roles of the lyric and dramatic repertoires.

Tebaldi was born Renata Ersilia Clotilde Tebaldi in Pesaro, the daughter of a cellist, Teobaldo Tebaldi, and Giuseppina Barbieri, a gifted singer who had wanted a singing career but eventually became a nurse instead. Very soon, the parents split up and Renata, together with her mother, moved to the latter's home town, Langhirano in the Province of Parma.

Stricken with polio at the age of three, Tebaldi was unable to take part in strenuous activities and instead became interested in music. She was a member of the church choir in Langhirano and her mother sent her to piano lessons with Signorina Passani in Parma at the age of thirteen; she worked with boundless diligence, practising four or five hours a day and dreaming of a career as a concert pianist. She also sang everything she heard. Her main source of inspiration was listening to the radio. It was not until her piano teacher took the initiative that Renata was sent to Italo Brancucci, a singing teacher at the conservatory of Parma. She began studying a short time later at the conservatory, taking lessons with Ettore Campogalliani for three years. Renata had to concentrate on scales and voice training for two years before she was allowed to learn the first songs towards the end of her second year of training.