I have seen SINGAPORE SUE and I believe that the title character was played by ANNA MAY WONG. I also believe that her singing voice was dubbed as well. Anna May Wong was the vastly underrated Asian-American actress from the silents to talkies to setting the precedent as the first Asian-American actress to star in her own tv series in the fall of 1951 for two months. She made one last movie, PORTRAIT IN BLACK, in 1960 then died in 1961 at the age of 56.