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.