Final answer:
Robert Johnson was indeed a pioneering blues musician whose guitar work influenced the development of rock & roll. The genre's mix of various musical styles played a critical role in blurring racial boundaries and challenging societal norms.
Step-by-step explanation:
It is true that Robert Johnson was one of the first musicians to perform the blues with a guitar and laid the foundation for many modern rock & roll techniques. Blues music, which evolved from African-American spirituals and reached new heights during the Harlem Renaissance, saw artists like Bessie Smith, known as "The Empress of the Blues," make significant cultural impacts. The birth of rock and roll, which blends electric instruments with the sounds of gospel, blues, country, jazz, and R&B, indeed blurred racial lines and led to cultural advancements, prompting societal changes that challenged segregation. The bricolage of musical influences from artists like Carl Perkins and Elvis Presley, who blended various styles such as gospel, blues, country, western, and R&B, showcased the genre's wide appeal across racial divides and contributed to rock and roll's rise to mainstream popularity.