The article is devoted to the unknown literary work of Sergey Mikhailovich Slonimsky—“Notes in the margins of the musical notebook”, written 20 years ago. In “Notes” the warning repeats over and over again: “not for printing.” The dramatic history covers the events of the second half of the 20th century. The 53-page typescript records the myths and reality of the artistic life of the USSR—Russia strictly chronologically. The confessional monologue is spoken in the first person, who received the author’s definition of “troublemaker against no one’s will.” Slonimsky says in his “Notes” that the 21st century is an era of “forgotten concealments with an unpleasant goal—to be prescribed in our history constantly against the background of less bright personalities, and to push the large, significant ones to the background.” That is why it was important for the composer to describe why he was forced to become a “troublemaker,” doomed to constantly defend himself.