The advent of sound in films, marked by the release of The Jazz Singer in 1927, revolutionized the entertainment industry. The talkies brought a new level of realism and emotion to the screen, and the major film studios, including MGM, Paramount, and Warner Bros., solidified their positions as industry leaders. This period, often referred to as the Golden Age of Cinema, saw the rise of iconic stars like Greta Garbo, Humphrey Bogart, and Marilyn Monroe, and the creation of timeless classics like Casablanca (1942) and Singin' in the Rain (1952).