Final answer:
Before rhythm and blues was referred to as such, it was known as race music up until the late 1940s, and it greatly influenced the birth of rock and roll which played a role in blurring racial lines and fighting segregation.
Step-by-step explanation:
Before it was known as rhythm and blues, the genre of music that led to the development of rock and roll was typically referred to as race music. This term was used up until the end of the 1940s to describe the music predominantly created by Black artists and marketed to Black audiences. This music form was rooted in various genres, including blues, jazz, and gospel and featured distinct rhythms and melodies that captured the attention of both Black and White audiences. Rock and roll music emerged as a direct evolution from these musical traditions, characterized by its heavy rhythm and simple lyrics. The growth of rock and roll brought together young people from diverse racial backgrounds and played a role in blurring racial lines, which contributed to social advancements and the fight against segregation. Sister Rosetta Tharpe and Jackie Brantson were among the important figures whose influences in the emergence of rock and roll cannot be overstated.