In her giddy ode to the first artists “to make black music popular music worldwide,” Hirshey describes the triumphs, woes and mammoth personalities of everyone from Screamin’ Jay Hawkins to Aretha Franklin — there’s even a rare interview with Michael Jackson. In tandem with lionizing these trailblazers, she examines how they helped establish Motown and Stax as the most cherished American labels of the boomer generation.