Her experience at the Met notwithstanding, Rhea became the first black performer to star in "the title role of a major opera company" when in Chicago on December 27, 1937 she appeared in Verdi's "Aida" with William Franklin as Amonasro in a performance of the Chicago Civic Opera Company. In attendance for the performance was the drama critic for the "Chicago Tribune" Cecil Smith, who commented: "A musical event without parallel in grand opera in America took place at the Civic Opera House last night when two colored singers, La Julia Rhea and William Franklin, sang the Ethiopian roles of Aida and Amonasro in a special performance of "Aida" ... Both singers won a goodly success and were warmly applauded." The costume Rhea wore for that performance was a gift from her teacher and mentor, the internationally renowned opera star Rosa Raisa, who had herself worn it at her debut performance of "Aida" in 1914. Both Rhea and Franklin appeared in productions of the National Negro Opera Company (NNOC), as well as in operettas by Gilbert and Sullivan. The production of "Aida" in which Rhea made the inaugural performance of the National Negro Opera Company in 1941 was organized by the NNOC Guild as part of Pittsburgh's National Association of Negro Musicians annual meeting. Mary Cardwell Dawson organized the event.