On one occasion, Chou showed his Chinese-flavored fugues to Bohuslav Martinů, who started to read them on the piano and suddenly stopped after a few measures. He looked at Chou and simply uttered one word: “Why?” Chou could not answer. Such an embarrassment disturbed him profoundly and made him realize that substituting pentatonic for heptatonic modes in fugue, which had been developed in the heptatonic and triadic tradition, was like putting Chinese words into Bach’s mouth. Fugue was Bach’s natural language, but not his. Chou believed that this was one of the greatest lessons he ever had because, beginning with the word “why,” he had to satisfy his own questions before moving on.