Jasper B. Chapin had built a 25 x 123 foot building on the northeast corner of Broadway and NP Avenue in 1878. It was destroyed in the fire of 1893.
The upper floor was used as a theater and was known as Chapin Hall. It became known as the Opera House in 1883 and largely supplanted McHench Hall as Fargo's major theater. Alex Stern purchased the the hall in 1888. Seating 800, the theater gave almost 400 presentations from Shakespeare to minstrel shows.
The photograph of the right was taken by F. J. Haynes on November 21, 1878.
Pictured below is a program of a production of "The Bohemian Girl" performed at the Opera House on December 20, 1884. The production was staged by the Fargo Musical Club and it appears that the performers were all Fargo residents. The only names that I recognize are Barnes and Shotwell. You may know other names.
The address shown (615 Front Street) is that of the sponsor of the program, not the address of the Opera House.