The article is devoted to the ballet theater of the outstanding composer of the XX-XXI centuries, Sergei Mikhailovich Slonimsky, which has not been sufficiently studied in musicological literature. On the example of the ballet “The Magic Nut” (“Princess Pirlipat or Punished Nobility” - in the first edition), the features of Slonimsky's musical Hoffmannianism, inspired by the idea of the famous artist Mikhail Shemyakin, who undertook to embody on stage (in libretto, scenography and costumes) the content of the fairy tale about the hard nut Hoffmann (in the short story “The Nutcracker and the Mouse King”). The article refutes the unfair criticism that both ballets were subjected to, proves the high artistic level of the implementation of Shemyakin's bold idea, which fully corresponds to the bright music of the ballet and its plastic and choreographic solution. The conclusions emphasize the idea of the synthesis of arts, typical of the aesthetics of romanticism and convincingly recreated in the performances of the Mariinsky Theater (2003 - Princess Pirlipat or Punished Nobility, conductor V. Gergiev, choreographer K. Simonov; 2005 - The Magic Nut, conductor M. Sinkevich, choreographer D. Pandursky).