Concern for the accurate synchronization of music and visual image increased during the 1920s. Devices designed to provide pre-set rhythmical cues to a conductor included Pierre de La Commune’s cinépupitre (used by Honegger) and Carl Robert Blum’s ‘rhythmonome’ (used in the staging of Krenek’s opera Jonny spielt auf in 1927). Gramophone recordings intended for synchronization with the projector were drawn from sound libraries, supplementing printed cue sheets for live music. In 1926 William Axt and David Mendoza composed a score for the Warner Brothers picture Don Juan, recorded by the New York PO on the Vitaphone disc system, and Warner’s commitment to disc-recorded soundtracks resulted in the first ‘talkie’: The Jazz Singer (1927), starring Al Jolson. The advent of the sound film brought with it the threat of unemployment for the many musicians who had established careers for themselves in cinema orchestras, and the novelty of the new medium temporarily put background scores out of fashion: music that appeared to emanate from the motion picture itself could be better justified if it were strictly diegetic in origin. In Hollywood, many early sound films included music only for opening and closing credits in addition to diegetic uses; as Max Steiner related, a violinist might be gratuitously included in the background of a love scene solely to justify the use of what would otherwise be invisible romantic underscoring.
An exception was the film musical, which grew out of the popularity of featured songs in dramatic films. The Broadway Melody (1929) and Sunny Side Up (1930) were among the first musicals composed specially for the screen, and within a few years choreographed routines had grown spectacular. Early highpoints were the work of Busby Berkeley (Gold Diggers of 1933), and Fred Astaire and Ginger Rogers, who filmed flamboyant interpretations of songs by Irving Berlin (Top Hat, 1935), Jerome Kern (Swing Time, 1936) and George Gershwin (Shall we Dance, 1937). After the success of The Wizard of Oz (1939), with songs by Harold Arlen and a score by Herbert Stothart, MGM produced lavish Technicolor musicals created by Vincente Minnelli and Gene Kelly, although examples specially written for the screen were rare after the mid-1950s when Broadway transfers became the norm.
The first sound films in Europe were Alfred Hitchcock’s Blackmail (1929), which was intially shot as a silent then partly remade to include a synchronized score, and René Clair’s Sous les toits de Paris (1929), both of which transferred the conventions of silent-cinema music more or less wholesale to the sound screen. More innovative were Milhaud’s score for Petite Lili (1929) and Georges Auric’s for Jean Cocteau’s Le sang d’un poète (1931). In Germany, early pioneers of a creative use of original diegetic music were Friedrich Hollaender and Karol Rathaus, who scored Der blaue Engel (1930) and The Brothers Karamazov (1931) respectively. Wolfgang Zeller contributed a substantial through-composed score to Carl Dreyer’s Vampyr in 1932. In the Soviet Union, early sound-film scores included Shostakovich’s Alone (1930) and Prokofiev’s Lieutenant Kijé (1933).
By the end of the 1920s new technology permitted sound to be recorded directly on to the celluloid strip carrying the visual image, and the Hollywood studios uniformly adopted the Western Electric process in 1930. Microphones were linked to either an oscillating lamp or a deflecting mirror in order to expose the soundtrack on film stock; during projection the soundtrack patterns were transformed into electric signals by a photo-electric cell. At first it was only possible for sound to be recorded simultaneously with the shooting of the visual image (with severe restrictions caused by inadequate microphones hidden on set and the need for the noisy cameras to be housed in sound-proof booths), but by the early 1930s sound could be dubbed after shooting, thereby opening up enormous creative potential. By the mid-1930s several tracks were available for the separate recording of dialogue, music and sound effects. Distortion was a serious problem when recording orchestral scores, and one reason why early soundtracks avoided complex textures and certain instruments; in Paris, the younger Adolphe Sax and Eric Sarnette developed special wind instruments with adjustable bells for studio recording, while Sarnette and Hanns Eisler abandoned string instruments. In the early 1930s the Germans Rudolph Pfenninger and Oscar Fischinger took the radical step of creating abstract musical tones with soundtrack patterns written by hand in an attempt to bypass the problems of recording fidelity and synchronization altogether, an experiment in ‘animated sound’ paralleled by inventors in the Soviet Union, England and elsewhere.
The potential for original extra-diegetic scores in dramatic pictures began to be realized in the USA as composers quickly developed a highly influential lingua franca of conventional orchestral film scoring. The idiom’s firm roots in 19th-century Romanticism were perpetuated by many immigrant European composers steeped in the styles of Wagner, Strauss and French Impressionism. The Hollywood studios featured highly active music departments, and at first several composers collaborated on single scores as a team. The first individual composer to win renown for his creativity was Max Steiner, a Viennese émigré who arrived in Hollywood in 1929 after working on Broadway (a common career move in the early years of the Depression). Steiner’s tentative score to Symphony of Six Million (1931) paved the way for his celebrated music for King Kong (1933). Traditionally viewed as the prototypical extra-diegetic score, King Kong featured a clear leitmotivic structure, illustrative music synchronized with specific on-screen activity, a degree of dissonance to suggest terror, and an intelligent use of silence to emphasize diegetic sound (notably in the climactic scene atop the Empire State Building, in which the sound of the biplanes’ machine guns predominates). All these characteristics have remained central to mainstream film music.