Classical Hollywood cinema
The beginning of the sound era itself is ambiguously defined. To some, it began with "The Jazz Singer", which was released in 1927 and increased box-office profits for films, as sound was introduced to feature films. To others, the era began in 1929, when the silent age had definitively ended. Most Hollywood pictures from the late 1920s to 1960s adhered closely to a genre—Western, slapstick comedy, musical, animated cartoon, and biopic (biographical picture)—and the same creative teams often worked on films made by the same studio. For instance, Cedric Gibbons and Herbert Stothart always worked on MGM films; Alfred Newman worked at Twentieth Century Fox for twenty years; Cecil B. DeMille's films were almost all made at Paramount Pictures; and director Henry King's films were mostly made for Twentieth Century Fox. Similarly, actors were mostly contract players. Film historians and critics note that it took about a decade for films to adapt to sound and return to the level of artistic quality of the silents, which it did in the late 1930s.
Dolby Laboratories
The first film with Dolby sound was "A Clockwork Orange" (1971), which used Dolby noise reduction on all pre-mixes and masters, but a conventional optical sound track on release prints. "Callan" (1974) was the first film with a Dolby-encoded optical soundtrack. In 1975, Dolby released Dolby Stereo, which included a noise reduction system in addition to more audio channels (Dolby Stereo could actually contain additional center and surround channels matrixed from the left and right). The first film with a Dolby-encoded stereo optical soundtrack was "Lisztomania" (1975), although this only used an LCR (Left-Center-Right) encoding technique. The first true LCRS (Left-Center-Right-Surround) soundtrack was encoded on the movie "A Star Is Born" in 1976. In less than ten years, 6,000 cinemas worldwide were equipped to use Dolby Stereo sound. Dolby reworked the system slightly for home use and introduced Dolby Surround, which only extracted a surround channel, and the more impressive Dolby Pro Logic, which was the domestic equivalent of the theatrical Dolby Stereo.