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. A success, he stayed with the show for most of 1911 when in toured the United States. He continued to perform in operas as well in 1911-1912 at Hammerstein's London Opera House, portraying Alfredo in Verdi's "La Traviata", Arnold Melchtal in Gioachino Rossini's "William Tell", the Duke of Mantua, Edgardo in Gaetano Donizetti's "Lucia di Lammermoor", Ferrando in Donizetti's "La favorite", Jean Grenicheux in Robert Planquette's "Les cloches de Corneville", Romeo in Gounod's "Roméo et Juliette", and the title role in Charles Gounod's "Faust".