Rimsky-Korsakov's editing of works by The Five is significant. It was a practical extension of the collaborative atmosphere of The Five during the 1860s and 1870s, when they heard each other's compositions in progress and worked on them together, and was an effort to save works that would otherwise either have languished unheard or become lost entirely. This work included the completion of Alexander Borodin's opera "Prince Igor", which Rimsky-Korsakov undertook with the help of Glazunov after Borodin's death, and the orchestration of passages from César Cui's "William Ratcliff" for its first production in 1869. He also completely orchestrated the opera "The Stone Guest by "Alexander Dargomyzhsky three times—in 1869–70, 1892 and 1902. While not a member of The Five himself, Dargomyzhsky was closely associated with the group and shared their musical philosophy.