the Italian version and it is one of the world's most frequently performed operas.In French as Le trouvère After the successful presentation of the opera in Italian in Paris, François-Louis Crosnier, director of l'Opéra de Paris, proposed that Verdi revise his opera for the Paris audience as a grand opera, which would include a ballet, to be presented on the stage of the major Paris house. While Verdi was in Paris with Giuseppina Strepponi from late July 1855, working on the completion of Aroldo and beginning to prepare a libretto with Piave for what would become Simon Boccanegra, he encountered some legal difficulties in dealing with Toribio Calzado, the impresario of the Théâtre des Italiens, and, with his contacts with the Opėra, agreed to prepare a French version of Trovatore on 22 September 1855. A translation of Cammarano's libretto was made by librettist Émilien Pacini under the title of Le trouvère and it was first performed at La Monnaie in Brussels on 20 May 1856. There followed the production at the Paris Opera's Salle Le Peletier on 12 January 1857 after which Verdi returned to Italy. Emperor Napoleon III and Empress Eugénie attended the latter performance. For the French premiere, Verdi made some changes to the score of Le trouvère including the addition of music for the ballet in act 3 which followed the soldiers' chorus, where gypsies danced to entertain them. The quality of Verdi's ballet music has been noted by scholar Charles Osborne: "He could have been the Tchaikovsky of Italian ballet" he states, continuing to praise it as "perfect ballet music". In addition, he describes the unusual practice of Verdi having woven in themes from the gypsy chorus of act 2, ballet music for opera rarely connecting with the themes of the work. Several other revisions focused on Azucena's music, including an extended version of the finale of act 4, to accommodate the role's singer Adelaide Borghi-Mamo. Some of these changes have even been used in modern performances in Italian. In 1990 Tulsa Opera presented the first staging of Le trouvère in the United States using a new critical edition by musicologist, conductor, and Verdi scholar David Lawton. Recorded live for broadcast on NPR, Lawton conducted the premiere with Margaret Jane Wray as Leonore, Craig Sirianni as Manrique, Greer Grimsley as Le Comte de Luna, Barbara Conrad as Azucena, and the Tulsa Philharmonic. This version was published