The song that Idina Menzel sings over the credits is a much-changed version of "Lullaby of Broadway," written by Al Dubin and Harry Warren. The song originally appeared in the Warner Brothers film Gold Diggers of 1935 (1935)and won the 1936 Academy Award for Best Original Song. It was one of many Warren and Dubin songs eventually included in the 1980 musical "42nd Street" (based mostly, but not entirely, on their 1933 movie of the same name). The version that Menzel sings in this documentary was arranged by Jan Folkson and Jeanine Tesori and given an almost entirely new tune, as well as some new lyrics - a spoken interlude drawn from Harlem Renaissance poet Claude McKay's 1920 poem "On Broadway;" Billy Porter performed the McKay portion of the song.