1. African American Music: Rock and roll draws heavily from African-American musical traditions, particularly blues, rhythm and blues (R&B), and gospel music. Musicians like Chuck Berry, Little Richard, and Fats Domino were pioneers in blending these genres with elements of Western music, forming the foundations of early rock n roll.
2. Country and Western Music: Country music, especially from the honky-tonk subgenre, had a considerable impact on the development of rock n roll. Artists such as Hank Williams and Elvis Presley blended country elements like the use of the electric guitar and the "backbeat" rhythm with the energy and rebellious spirit of rock music.
3. Jazz and Swing: Jazz and big band music also played a role in shaping the stylistic elements of early rock n roll. The use of saxophone, trumpet, and improvised solos, as well as swing rhythms, can be heard in many early rock and roll recordings.
4. Doo-Wop and Vocal Harmonies: Doo-wop, an urban vocal harmony style popular in the 1940s and '50s, greatly influenced the vocal approach in early rock n roll. Groups like The Platters and The Penguins, with their rich vocal harmonies and R&B influence, served as precursors to the vocal styles of rock and roll.
5. The Post-World War II Era: The economic and social changes following the end of World War II created an environment receptive to new forms of music. Increased disposable income and the rise of a youth culture, along with the development of new recording technologies, contributed to the widespread appeal and popularity of rock n roll.
These factors and musical roots fused to create what we now know as rock n roll, which had a transformative impact on music and culture, ultimately becoming a global phenomenon.