Symphony Hall, Boston
In Chicago, Dufau was a lead soprano, nicknamed the "smallest soprano". She performed in operas such as "Die Walküre", "The Barber of Seville", and "I gioielli della Madonna". In 1914, she sang the title role in Massenet's "Manon" for the Boston Opera Company. In 1916, Dufau moved to New York, and shifted her focus to singing concerts nationwide, notably at the Ravinia Festival, Hamilton Park (Chicago), and Symphony Hall, Boston. The American composer Frank La Forge wrote songs for her, which she performed at these concerts. Dufau wrote songs for her concerts, including "A Soldier I Shall Be", a patriotic wartime anthem.