Mikalojus Konstantinas Čiurlionis (1875-1911) was a prominent Lithuanian composer and a painter of international renown. During a brief ten-year period of musical activity and six years devoted to painting, he created around 350 musical compositions and 300 paintings. The paper aims to outline the stylistic aspects of his work and situate it within the broader context of early 20th-century art. The influence of late Romanticism, Symbolism, Theosophy, Orientalism, and Expressionism on the work of Mikalojus Konstantinas Čiurlionis is examined. Čiurlionis’s musical works are characterized by a late-Romantic style that evolves toward an atonal musical language and Expressionism. He was among the first composers to employ elements of serial technique, anticipating A. Schoenberg. Čiurlionis’s symphonic poem The Sea is comparable in the quality of its artistic imagery to the Impressionist C. Debussy’s La mer. Čiurlionis’s seven cycles of pictorial sonatas, his “vision of music,” and his “hearing of colors” invite comparison with other notable cases of synesthesia, such as those of A. Scriabin and O. Messiaen. The interaction between melodic and pictorial lines will be examined, along with the reflection of musical sonata and fugue forms in painting. Particular attention will be given to his series of paintings Sea Sonata, the symphonic poem The Sea, and the literary work (a prose poem) The Sea. The conclusion of the paper offers pedagogical implications for music education, presenting several simple methods for developing conscious listening to Čiurlionis’s music and aesthetic appreciation of his paintings.Keywords: Čiurlionis, composition, musical painting, pictorial sonatas, synesthesia