Stage Poetry. Music Actions. Although Brossa's stage poetry is one of the most important creative achievements of 20th-century Catalan theatre, it is undoubtedly still one of the least explored realms of his production. With his theatre actions, his music actions, the dance pieces and his monologues of transformation, Brossa is a clear precursor of the happening, performance and action art. On the basis of formal criteria, the Stage poetry has been divided into six main blocs: Teatre literari (1944-1965); Postteatre (Post-theatre) (1946-1962), a series of stage actions; Ballets o Normes de mascarada (Ballets or Mascarade Norms) (1948-1964); Fregolisme o monòlegs de transformació (Fregolism or Monologues of Transformation) (1965-1966); Striptease i teatre irregular (Strip-tease and Irregular Theatre) (1966-1967), and Accions musicals (Music Actions) (1962-1993), most of them created in collaboration with the composers Josep M. Mestres Quadreny and Carles Santos.