EN
The operetta 'Apollo Prawodawca, czyli Parnassus Reformowany' (Apollo the Law-Giver, or the Parnassus Reformed) is the only musical drama surviving from among numerous works which used to be performed on the stages of school theatres in the Commonwealth of Poland and Lithuania in the eighteenth century. The article attempts to define the genre of 'Apollo', which combines features of two theatrical genres, i.e. the operetta (since it contains relatively small structural forms), and the intermedium (the individual parts of which could be performed between the acts of another stage play). The operetta 'Apollo', staged to celebrate the end of the school year with the aim of acquainting pupils with the rules of oratory, copies the pattern of the school play with a didactic function, and displays features of two closely related musical genres widely employed in the art of the seventeenth and eighteenth centuries - the operetta and the intermedium.