The decline and fall of the idea of progress intensified interest in the problems of nationalism. Stravinsky in his 'Poetics of Music' identified universality with a harmony of diversity governed by the idea of beauty, goodness and truth, while cosmopolitanism was associated for him with a lack of sense of community and the rejection of cultural tradition, with the anarchy brought about by the 'monster of originality', the so-called progressive art, which made a radical break with the traditional system of values. In fact, not only avant-garde music achieved the status of supranational, cosmopolitan art, but also neoclassicism of the inter-war period was associated with the concept of supranational music. On the other hand, both currents were also marked by nationalistic thinking. The authoress presents various interpretations of 20th-century uses of the term to define the concept of 'national music'.