The life of the Teatro de São Carlos entered a new phase immediately after the revolution of 25 April 1974. That same year, João de Freitas Branco, director since 1970, took up governmental functions and was replaced by João Paes, who in 1981 would in turn be succeeded by José Serra Formigal, who between 1963 and 1975 had led the Companhia Portuguesa de Ópera based at the Teatro da Trindade. He appointed Mário Moreau (1982–1984) and João de Freitas Branco (1985–1988) as artistic directors, leaving the position in 1988 upon the appointment of a new board of administration. The role of artistic director was then entrusted to José Ribeiro da Fonte until 1992, the year in which the public company of the Teatro Nacional de São Carlos was dissolved, having been created in 1980 and now replaced by the Fundação de São Carlos¹.
During this period, a project was undertaken to establish a resident company associated with its own artistic forces. From 1975 onwards, casts increasingly featured the leading Portuguese singers of the time (such as Elisette Bayan, Carlos Fonseca, José Oliveira Lopes, Álvaro Malta, Helena Pina Manique and Fernando Serafim), many of whom transferred from the aforementioned company of the Teatro da Trindade, later joined by younger singers at the beginning of their careers. In that same year, much of the former Orquestra Filarmónica de Lisboa was incorporated into the formation of a new ensemble that would later become known as the Orquestra Sinfónica do Teatro Nacional de São Carlos. A ballet company was also created. As for the repertoire, from 1974 onwards there was an increase in national premieres of works from the Baroque and contemporary repertoire, with particular emphasis, during Serra Formigal’s tenure, on the presentation of national operas or foreign works in Portuguese, using casts of Portuguese singers alongside foreign performers. However, under the subsequent artistic direction of Ribeiro da Fonte, efforts shifted towards the internationalisation of the theatre’s activity, with a preference for attracting renowned international artists, accompanied by a reduced interest in in-house productions².
