No one doubts the importance of Stravinsky's work for development of musical theatre. Some prominent scholars, however, still see his works for theatre as 'chiefly musical compositions'. In reality, it is the theatre component that constitutes Stravinsky's works for stage. Not only he knew the Avant-garde theatre well, but already in the Act One of Le Rossignol, he reinvents himself as a creator of musical theatre with specific aesthetic views, admirable taste and originality. In Stravinsky's works, music and theatre share common rules of the game. The principle of 'Trennung der Elemente' (Brecht) and Stravinsky's 'paradoxical' handling of historical and folklore models is applied throughout the work. In addition, the Renard and Mavra sketches prove that Stravinsky applied his tectonical structuring paralelly in music and the text. His abrupt alternation of blocks dissolves the traditional logical structure of an art piece in both music and theatre.