Final answer:
The new middle class music emerged from a combination of numerous cultural and musical influences, with a marked shift during the Romantic period from aristocratic audiences to public concerts. The advent of rock 'n' roll in the 1950s was propelled by the youthful energy of a technologically enhanced society and the consumer culture of an affluent middle class. The growth in leisure activities and popular culture settings like Tin Pan Alley and jazz clubs also played significant roles in the evolution of American music.
Step-by-step explanation:
The new middle class music was based on a diverse blend of cultural and musical influences that evolved with the socioeconomic changes of the times. During the Romantic period, the shift from aristocratic patronage to public concerts made classical composers write for a broader, less specialized audience. However, by the 20th century, particularly in the 1950s, the rise of rock 'n' roll epitomized the energetic youth culture. It was originally rooted in African American genres, such as gospel, blues, jazz, and R&B, and became widely popular through technological advancements that facilitated recording and distribution, alongside the consumer culture of a growing middle class.
The combination of electric instruments and various American musical traditions gave rock 'n' roll its distinctive sound, appealing massively to teenagers. Further cultural influences came from the festive and public cultures of the working class, including taverns and public entertainment, and the increasing leisure activities such as sports and shopping that the urban middle class engaged in. This rise in leisure culture also contributed to the development of new musical genres and the spread of existing ones, like jazz, which transitioned from African American communities to wider urban popularity.
Musical tastes also grew with new social trends and technologies, leading to increased demand for musical products. The need for pianos in middle-class homes, for example, drove the market for ivory, and new musical fashions such as opera and baroque music flourished in the prosperous cities of Europe. In the United States, popular culture arenas like Tin Pan Alley and the Cotton Club were influential in shaping and spreading new music, notably ragtime and jazz, which ultimately laid the groundwork for future American music genres.