Final answer:
The statement is False; theater design and technology continually evolved throughout the early and mid-twentieth century, influenced by realism, cinema, and the diversification of the audience and society.
Step-by-step explanation:
The statement that the physical features of theaters in the early and mid-twentieth century remained relatively unchanged from the advances made in the nineteenth century is False. Theatre architecture and design continued to evolve with technological advancements and societal changes. Theatrical spaces in the nineteenth century had already begun to cater to a wider audience with a variety of seating options and stages designed for elaborate scene changes and to attract diverse classes of society. However, as the twentieth century progressed, so did technology and the social fabric of society.
The Realism movement, inspired by social thinkers like Darwin, Marx, and Freud, demanded more historically accurate scenery and costumes, mirroring society. Hence, sets and stage machinery became more sophisticated to accommodate realistic productions. The cinema boom, particularly with the advent of talkies and advances in film technology, greatly influenced the evolution of theatrical spaces. Theaters began to incorporate technology for sound and lighting that was not previously available or necessary for silent films and traditional stage plays.
Furthermore, the rise of musical theatre and vaudeville demanded spaces with specific acoustic and stage requirements. Similarly, the inception of African American Theatre and the popularity of shows like 'In Dahomey' reflected the industry’s adaptation to social changes and the rising demand to reflect a more diverse society. The automobile's mass production in the 1920s, exemplified by Ford’s Model T, reflected the era's technological progressiveness that also swept through the theater industry. Theater designs had to keep up with these various societal and technological shifts, disproving the notion of architectural stagnation during the early to mid twentieth century.