The paper is an attempt to find the mythical roots of the prose works "Tristan" by Thomas Mann and "Tristan 1946" by Maria Kuncewiczowa. The undertaken analysis has shown that the titles of both works are a conscious provocation or a pretext for taking a broader perspective on the essence and the role of myths in the modern world. In his polemic discussion with Wagner contained in his short story written in a sanatorium Thomas Mann seems to reach similar conclusions as Maria Kuncewiczowa, who in her Cornish novel invokes autobiographical motives. The love of Tristan and Isolde of the 20th century is doomed to fail. The medieval myth is confronted with the ancient myth (in the work by Thomas Mann) and with the modern bourgeois myth of family. Both Thomas Mann and Maria Kuncewiczowa intuitively sense and anticipate the theory by Levi-Strauss by showing how in the modern world devoid of love the music replaces the myth, takes over its function and becomes an illusory light at the end of the tunnel.