The author explores the pioneering ideas and experiments that the Russian musician and artist Mikhail Matyushin (1861–1934) contributed to the theory and practice of synthetic art. Special emphasis is placed on light art, light music and Matyushin's reflections on analogies between visual and performance art and on synesthesia. The article adduces some new facts, taken mainly from Russian sources not readily accessible to Western researchers. Although Matyushin did not make a significant contribution to the cause of actual lightmusical synthesis, he did make interesting forecasts in this area, which still have value for the modern reader.