After appearing in several operetta productions in minor theatres and singing in cabaret performances in New York City for a few years, Harrold finally had a big break in his career when he drew the attention of Oscar Hammerstein I in 1909.
In November 1910 Harrold returned to performing the operetta repertoire when he starred as Captain Dick Warrington in the first production of Victor Herbert's Naughty Marietta opposite Emma Trentini in the title role at the New York Theater.