His piano work of the early 1940s, "Ludus Tonalis" contains twelve fugues, in the manner of Johann Sebastian Bach, each connected by an during which the music moves from the key of the last fugue to the key of the next one.
His piano work of the early 1940s, "Ludus Tonalis" is seen by many as a further example or exploration of this system. It contains twelve fugues, in the manner of Johann Sebastian Bach, each connected by an during which the music moves from the key of the last fugue to the key of the next one.