With a first-night audience clapping and bellowing with joy at the end of his first picture, at the Warner Theatre, Mr. Al Jolson stepped to the front of the stage with a tear in his eye and said he was glad they liked it. The film was "The Jazz Singer" and probably nobody liked it much... The shouting was about Mr. Jolson and the Vitaphone. I have said a lot of unpleasant things about the Vitaphone, but all my words are eaten.The Vitaphone was a record carefully synced up with a reel of film; the record and the film played simultaneously, and the sound was amplified and played into the theatre. It was (at the time) the most effective way of syncing film and audio together, but it took two years before Warner Brothers found the right way to apply the process.
One limitation appeared to be that the sound needed to be "dubbed" by the performer, instead of recorded live at the same time as the filming. So it wasn't deemed practical to recall actors to re-speak their lines and try to sync them with the original film recording. Perhaps this was more complicated because the idea of "dialog" in a movie was an extremely loose one; the actors often ad-libbed (or babbled) during the filming, relying on the subtitles to tell the story.
For this reason it was probably considered more practical to only use the Vitaphone when exact synchronization wasn't necessary.
Previously, the film critic for The New Yorker had mentioned those applications for the vitaphone: playing marching music when the soldiers march home on-screen, for instance, or playing the sound of a motorcycle during a slapstick chase scene. But audiences accustomed to silent films found these intrustions noisy and weird.
It took "The Jazz Singer," with its musical interludes, to strike a comfortable balance and open the door to a new concept. And it took Al Jolson to perfectly dub his singing and his dialog into the Vitaphone.
That evening will probably turn out to be an epochal one in the history of the movies, for questions were answered and questions were raised. True, the speaking movie is not so new; but hitherto it has been a novelty without much grip. Now it has shown what it can do... An article in a recent Variety mentions spoken sub-titles, but that will not prove to be enough. In "The Jazz Singer" after the singing, or after a short bit of dialogue, the silent mouthings of the characters seemed flat and silly. A new and fertile field of writing, acting, and directing is in view, with possibilities that can hardly be guessed. Will the spoken film have to aim at two audiences, the metropolitan and the rural, instead of one as now?--and consequently make two separate types of pictures, one for the city people and one for those in the country?He's correct that audiences would no longer be satisfied with the "flat and silly" silent films, but he's actually wondering if "metropolitan" audiences would remain loyal to silent films and "rural" audiences would demand the spoken film. This says something about either the snobbishness of "metropolitan" audiences...or, more likely, the snobbishness of film critics.