The article considers the creativity of the abstractionist artist František Kupka (1871-1957) in the context of synthesis of visual and musical aspects. The role of musical analogies in the genesis of Kupka’s language of abstract art in the first third of the 20th century is reviewed. Music seems to be an important conceptual and expressive element of Kupka's non-figurative works. Musical analogy is a way of solving several related problems: rejection of representation of forms of reality; introduction of a temporal dimension into the space of the work of plastic art; and achievement of a "mystical" effect intended by the artist. It is shown how the idea of musical analogy is realized at practical level