A sound film is a motion picture with synchronized sound, or sound technologically coupled to image, as opposed to a silent film. The first known public exhibition of projected sound films took place in Paris in 1900, but decades passed before sound motion pictures became commercially practical. Reliable synchronization was difficult to achieve with the early sound-on-disc systems, and amplification and recording quality were also inadequate. Innovations in sound-on-film led to the first commercial screening of short motion pictures using the technology, which took place in 1923. The sound film was also played with organs or pianos in the actual movie to represent sound. The primary steps in the commercialization of sound cinema were taken in the mid-to-late 1920s. At first, the sound films which included synchronized dialogue, known as "talking pictures", or "talkies", were exclusively shorts. The earliest feature-length movies with recorded sound included only music and effects. The first feature film originally presented as a talkie (although it had only limited sound sequences) was The Jazz Singer, which premiered on October 6, 1927. A major hit, it was made with Vitaphone, which was at the time the leading brand of sound-on-disc technology. Sound-on-film, however, would soon become the standard for talking pictures. By the early 1930s, the talkies were a global phenomenon. In the United States, they helped secure Hollywood's position as one of the world's most powerful cultural/commercial centers of influence (see Cinema of the United States). In Europe (and, to a lesser degree, elsewhere), the new development was treated with suspicion by many filmmakers and critics, who worried that a focus on dialogue would subvert the unique aesthetic virtues of silent cinema. In Japan, where the popular film tradition integrated silent movie and live vocal performance (benshi), talking pictures were slow to take root. Conversely, in India, sound was the transformative element that led to the rapid expansion of the nation's film industry.