What music style began in the late 1940s and was characterized by an emphasized backbeat?

Rock and roll  music style began in the late 1940s and was characterized by an emphasized back beat.

Explanation:

Rock music is an expansive kind of famous music that began as shake and move in the United States in the mid 1950s, and formed into a scope of various styles during the 1960s and later, especially in the United States and the United Kingdom.

It has its underlying foundations in 1940s and 1950s shake and roll, a style which drew intensely. From the 1990s elective shake started to rule shake music.