Final answer:
The “Roaring Twenties” or the “Jazz Age” fueled the Big Band Era with its exuberant social and cultural changes, but also set the stage for its downfall due to shifts towards consumerism and the eventual economic crash of the Great Depression.
Step-by-step explanation:
The social event that both fueled the Big Band Era and foreshadowed its demise was the flourishing lifestyle and culture of the “Roaring Twenties” or the “Jazz Age.” During this time, the proliferation of jazz music, spearheaded by African American communities, reached widespread popularity. Black jazz bands like the King and Carter Jazzing Orchestra became immensely popular, particularly among white urbanites. Figures like flappers and sheiks symbolized a new era of social freedom and cultural expression, often found at jazz clubs like the Cotton Club in New York City.
The same cultural explosion that spread the popularity of jazz music also contributed to the lifestyle that would herald its decline. As the 1920s progressed, the flapper era began representing both a triumph in women's rights and a shift in social norms. The 1920s saw women achieving greater political power with the ratification of the Nineteenth Amendment and embracing new forms of social expression, including jazz.
Moreover, American society in the 1920s was increasingly unified by national consumer culture. People across the country listened to the same music, embracing jazz as a core part of the era's identity. Yet, the same technological advancements and national media that helped spread jazz also precipitated a move towards other forms of entertainment and consumerism. The end of the 1920s brought about the Great Depression, which undermined the economic foundation that allowed the indulgence in lavish entertainments like those provided by big bands.