In Hard Bop, the first thorough study of a brand of post-bebop jazz that included many of the most talented American musicians from roughly 1955 to 1965, David H. Rosenthal vividly examines the roots, traditions, explorations and permutations, personalities and recordings of a climactic period in jazz history. Beginning with hard bop's origins as an amalgam of bebop and R&B, he describes the evolution of movement that welcomed all influences.