The musical retained Lee's "central theme – a theme coursing through much 20th-century American literature: the conflict between Old World immigrants and their New World offspring". Hammerstein and Fields shifted the focus of the story, however, from the elder Wang, who is central to Lee's novel, to his son Ta. They also removed the darker elements of Lee's work, including Helen Chao's suicide after her desperate fling with Ta, added the festive nightclub subplot and emphasized the romantic elements of the story. According to David Lewis in his book about the musical, "Mr. Hammerstein and his colleagues were evidently in no mood to write a musical drama or even to invest their comedic approach with dramatic counterpoint of the sort that Jud Fry had given "Oklahoma!" ... took the safest commercial route by following the eldest son's search for love – the most popular theme at the time with Broadway audiences." Lewis notes that Chao's role, though diminished in the musical, nevertheless gives it some of its darkest moments, and she serves much the same purpose as Jud Fry: to be, in Hammerstein's words, "the bass fiddle that gives body to the orchestration of the story". Though the new story was less artistically adventurous than the earlier Rodgers and Hammerstein hits, it was innovative, even daring in its treatment of Asian-Americans, "an ethnic group that had long been harshly caricatured and marginalized in our mainstream pop culture."