On September 17, 1922, the Tri-Ergon group gave a public screening of sound-on-film productions—including a dramatic talkie, "Der Brandstifter" ("The Arsonist") —before an invited audience at the Alhambra Kino in Berlin. By the end of the decade, Tri-Ergon would be the dominant European sound system. In 1923, two Danish engineers, Axel Petersen and Arnold Poulsen, patented a system that recorded sound on a separate filmstrip running parallel with the image reel. Gaumont licensed the technology and briefly put it to commercial use under the name Cinéphone. Domestic competition, however, eclipsed Phonofilm. By September 1925, De Forest and Case's working arrangement had fallen through. The following July, Case joined Fox Film, Hollywood's third largest studio, to found the Fox-Case Corporation. The system developed by Case and his assistant, Earl Sponable, given the name Movietone, thus became the first viable sound-on-film technology controlled by a Hollywood movie studio. The following year, Fox purchased the North American rights to the Tri-Ergon system, though the company found it inferior to Movietone and virtually impossible to integrate the two different systems to advantage. In 1927, as well, Fox retained the services of Freeman Owens, who had particular expertise in constructing cameras for synch-sound film. Parallel with improvements in sound-on-film technology, a number of companies were making progress with systems that recorded movie sound on phonograph discs. In sound-on-disc technology from the era, a phonograph turntable is connected by a mechanical interlock to a specially modified film projector, allowing for synchronization. In 1921, the Photokinema sound-on-disc system developed by Orlando Kellum was employed to add synchronized sound sequences to D. W. Griffith's failed silent film "Dream Street". A love song, performed by star Ralph Graves, was recorded, as was a sequence of live vocal effects. Apparently, dialogue scenes were also recorded, but the results were unsatisfactory and the film was never publicly screened incorporating them. On May 1, 1921, "Dream Street" was re-released, with love song added, at New York City's Town Hall theater, qualifying it—however haphazardly—as the first feature-length film with a live-recorded vocal sequence. There would be no others for more than six years. In 1925, Sam Warner of Warner Bros., then a small Hollywood studio with big ambitions, saw a demonstration of the Western Electric sound-on-disc system and was sufficiently impressed to persuade his brothers to agree to experiment with using this system at New York City's Vitagraph Studios, which they had recently purchased.