Morgan Wright defined the difference between Rock and other forms of R and B as being in the underlying rhythm: "While being eight to the bar, there is a slight lag between the bars. The pause between the bars builds up tension---the first beat of the new bar is held back, whereupon the 2nd beat of each bar is slammed with extra force, thus making it rock."

This makes Rock and Roll edgier than the bouncy sound of something like Fats Domino's Jump Blues style, which come down hard on the 'one.'