Later on, Herfort was first violin and viola of the New York Philharmonic Society (now the New York Philharmonic) and the New York Symphony Orchestra. For many years, he was the orchestra leader of the Metropolitan Opera. He was also the director of the vaudeville theater Koster and Bial's Music Hall and the Long Beach Hotel, at its beginning and at the height of its popularity. He was the former musical director for E. H. Sothern and Sarah Bernhardt Productions, and was a member of the Aschenbrödel Verein, a musical society. In addition, Herfort was a member of the Venth-Kronold String Quartet, founded and led by the musician Carl Venth, in which Herfort played viola.
