She specialized in roles requiring beauty of tone, excellent breath support, and the ability to execute difficult coloratura passages.

[5] Bentz was also a semi-professional singer and, noticing Marilyn's talent, sought to move the family to a place where she could have access to professional vocal training and more opportunities to perform.

[6] As a high school student, she was part of the St. Luke's Episcopal Church Choir of Long Beach under the direction of William Ripley Dorr.

[14][15] Horne's first major professional engagement was in 1954, when she dubbed the singing voice of Dorothy Dandridge in the film Carmen Jones.

[3] Until that point, she had worked as a background singer for several TV sitcoms, as well as recorded covers of popular songs of the early 1950s, which were sold in dimestores around the country for $1.98.

She made an appearance on The Odd Couple as a character named "Jackie", her own nickname, a meek and nervous would-be singer who develops a crush on character Oscar Madison (Jack Klugman) and into a full-blown diva as well, playing the role of Carmen in Felix Unger's (Tony Randall) opera group production.

Her first major breakthrough came when her singing ability was recognized by Igor Stravinsky; her operatic career began when he invited her to perform in the 1956 Venice festival.

[3] They first performed together in a concert version of Vincenzo Bellini's Beatrice di Tenda at The Town Hall in Manhattan in February 1961.

She can be heard on the soundtrack of the 1961 film Flower Drum Song singing "Love, Look Away" and she sang the role of Lady Thiang on the Philips recording of The King and I starring Julie Andrews and Ben Kingsley.

In January 1993, Horne sang "Make A Rainbow" by American singer and songwriter Portia Nelson, and the Shaker hymn "Simple Gifts" at the inauguration of President Bill Clinton.

[21] The creation of the Marilyn Horne Museum and Exhibit Center in the Pitt Bradford campus’ Seneca Building (now Marilyn Horne Hall) was partially made possible through a $3 million grant the McKean County Industrial Development Authority received from the Commonwealth of Pennsylvania's Redevelopment Assistance Capital Program in 2013.

[22] Since opening on May 6, 2017, the museum publicly displays a rotating portion of the collection at the regional campus in Bradford, from which she received an honorary degree in 2004.

[27] Her mother initially had misgivings that the interracial marriage would have a negative impact on Horne's career, saying, "Be his mistress, for God's sake, not his wife," but soon reconciled with them.