By World War I, musical tastes were shifting in America, and Herbert was forced to compose in a simpler musical style. Many of his later works, such as "The Velvet Lady" and "Angel Face" (both 1919), imitated popular new song-types like the foxtrot, ragtime and the tango. Even in some of his earlier works, such as "The Red Mill" (1906), Herbert was already adopting elements that would later become associated with musical comedy in America. His collaboration on "The Century Girl" (1916) with Irving Berlin displayed this simpler style. Although these later shows introduced some memorable numbers, they did not enjoy the enduring popularity of his most popular operettas. The most successful work of his later career was "Orange Blossoms" (1921), which included the popular waltz song, "A Kiss in the Dark".