This is a study on the microtonal aspects of Gy rgy Ligeti's Hamburgisches Konzert (Horn Concerto), with special reference to its relationship with the American composer Harry Partch, but also with G rard Grisey and Claude Vivier. The special mixture of equal temperament versus just intonation is analyzed. The movement "Choral" is confronted with Harry Partch's idea of "tonality flux". The work is shown with its inherent long chain of exploratory...