Why did musical films become popular after sound was introduced to cinema?

The introduction of sound to cinema was a transformative event that directly enabled the emergence of the musical film as a major genre.1

Musical films became popular for several key reasons:

• Technological Novelty: The ability to record and synchronize sound allowed filmmakers to capture music and dialogue, which audiences found thrilling. Early sound films, such as The Jazz Singer (1927), served as catalysts for this shift, leading studios to produce musicals to capitalize on the public's fascination with the new medium.213
• Adaptation of Existing Forms: The genre drew heavily from established stage traditions, including Broadway musicals, vaudeville, and operetta. By adapting these popular stage hits, studios could leverage familiar content and talent to attract audiences to the new sound format.14
• Formal Sophistication: As the technology matured, the musical evolved from simple transcriptions of stage performances into a sophisticated cinematic art form. Directors and choreographers, such as Busby Berkeley and Fred Astaire, developed elaborate dance sequences and integrated music into the plot, establishing the musical as a dominant genre of the 1930s.13