In the mid- to late '40s, Black popular music began to mutate from swing jazz and boogie woogie into the sort of rhythm & blues that helped lay the foundation for rock & roll. Singer and pianist Hadda Brooks was one of the many figures who was significant in aiding that transition, although she's largely forgotten today. While her torch song delivery was rooted in the big-band era, her boogie woogie piano looked forward to jump blues and R&B. Ironically, the same qualities that made her briefly successful -- her elegant vocals and jazzy arrangements -- left her ill-equipped to...