What Austro-Hungarian composer helped produce "Princess Flavia" and "New Moon"?
Princess Flavia: Princess Flavia is a 1925 operetta in three acts based on Anthony Hope's novel "The Prisoner of Zenda", with book and lyrics by Harry B. Smith and music by Sigmund Romberg. Sigmund Romberg:  He is best known for his musicals and operettas, particularly "The Student Prince" (1924), "The Desert Song" (1926) and "The New Moon" (1928).
Sigmund Romberg