The paper explores the question of musical melodism - a very relevant issue of today's musical culture. Our attention is focused on «King Lear», a new opera by Sergey Slonimsky written in the genre of monadic drama (2001), based on the Shakespeare's tragedy (in the Russian translation by Boris Pasternak). Based on this example, we explore the characteristics of melodism and highlight the original traits of the composer's declamation and cantilena operatic style. The authors come to the conclusion that «King Lear» provides a seamless integration of European and Russian operatic cultural tradition of 16th-17th and 19th-20th centuries.