Final answer:
Fifties rhythm-and-blues songs typically featured bands with a mix of electric instruments that contributed to the development of rock and roll. This new American music genre had a heavy rhythm and focused on themes of youth and freedom, growing popular with the help of influential radio DJs.
Step-by-step explanation:
In a fifties rhythm-and-blues song, we expect to hear bands that incorporate a combination of electric instruments such as the electric guitar and the electric bass, along with drums, saxophones, and pianos. This combination contributed to the emergence of rock and roll, which integrated elements from gospel, blues, country, jazz, and R&B to produce a new sound that resonated with teens across the nation.
Influential figures like Sister Rosetta Tharpe and Jackie Brantson, alongside pioneering bands like Bill Haley and His Comets and iconic artists such as Chuck Berry, helped shape the new sound of rock and roll. These bands and artists utilized the electric guitar for its capacity to be amplified and its versatility in creating solos that captivated listeners.
The new genre of rock and roll was marked by a heavy rhythm, simple lyrics, and melodies that often celebrated youth, love, and freedom. It was a unique American form of music that grew in popularity thanks to the efforts of disc jockeys like Alan Freed, who played rhythm-and-blues and rock-and-roll music on the radio, propelling it to national acclaim.