In the latter part of her career her voice acquired a contralto-like darkening, which can be heard on her recording of Sergei Prokofiev’s Alexander Nevsky with conductor Eugene Ormandy and the Philadelphia Orchestra.

Her father was a college educated math teacher who worked in a steel mill as racial prejudice prevented him from being hired in the public school system during the 1930s.

[4] Allen's next forray into opera came on June 6, 1954, when she participated in the world premiere of Sam Raphling's Tin Pan Alley on a radio broadcast on WNYC.

[5] On July 1, 1954, she sang the part of Prince Orlofsky in a concert version of Johann Strauss II's Die Fledermaus at the Lewisohn Stadium under conductor Tibor Kozma.

[3] In January 1955 Allen sang the part of the Israelite Messenger in Handel's Judas Maccabaeus with tenor Walter Carringer in the title role, the Interracial Fellowship Chorus, and conductor Harold Aks.

[7] With The Dessoff Choirs and conductor Paul Boepple she was a soloist in Claudio Monteverdi's Vespro della Beata Vergine 1610 in a concert sponsored by the Baron Carlo de Ferraris Salzano, Consul General of Italy at Carnegie Hall on April 28, 1955.

[13] In 1961 Allen sang Teresa to the Amina of Joan Sutherland in the American Opera Society's production of La sonnambula at Carnegie Hall.

[14] She performed with the AOS again the following year as Baba the Turk in Stravinsky's The Rake's Progress with Alexander Young as Tom Rakewell, John Reardon as Nick Shadow, and Judith Raskin as Anne Trulove.

[17] She returned to AOS again in 1965 to sing Zaida in Rossini's Il turco in Italia with Giorgio Tadeo as Selim, Judith Raskin as Fiorilla, Elfego Esparza as Don Geronio, Jerold Siena as Narciso, and Sherrill Milnes as Prosdocimo.

[18] That year she also portrayed Clitemnestre in Gluck's Iphigénie en Aulide at the AOS with Christa Ludwig in the title role, Richard Cassilly as Achille, and Walter Berry as Agamemnon.

She made her San Francisco Opera debut two years later as Azucena in Il trovatore with McHenry Boatwright as the Count di Luna, later reprising that role with the company in 1971.

She was committed to the New York City Opera from 1973 to 1975 where her roles included Azucena, Mistress Quickly in Falstaff, Jocasta in Oedipus rex, and Eurycleia in Il ritorno d'Ulisse in patria.

At the Santa Fe Opera Allen sang Pythia in Aribert Reimann's Melusine and Genevieve in Claude Debussy's Pelléas et Mélisande in 1972.

[23] She made her debut at the Metropolitan Opera as the Commère on February 20, 1973, in a cast that included Clamma Dale as St. Teresa I, David Britton as St. Stephen, and Barbara Hendricks as St.

Other roles in her repertoire included Sesto in La Clemenza di Tito, the Sorceress in Dido and Aeneas, and Ulrica in Verdi's Un ballo in maschera.

Her concert work led to collaborations with such conductors as Pierre Boulez, Pablo Casals, Edo de Waart, Antal Doráti, István Kertész, Rafael Kubelík, Erich Leinsdorf, Lorin Maazel, Charles Munch, Eugene Ormandy, Seiji Ozawa, Georg Solti, Leopold Stokowski and Enrique Gimeno.

Allen's professional singing career was cut short by chronic lung problems which she blamed on her exposure to the Campbell, Ohio steel mills in her childhood.