One of the central questions of popular music history, and one that fans and critics never tire of asking, is eternal: when did rock & roll start? Time Life smartly sidesteps the question on Roots of Rock: 1945-1956 by issuing a number of R&B hits that would feed into the rock revolution. Whether some of the songs, like Jackie Brenston & His Delta Kings' "Rocket 88," might actually be rock & roll will have to be decided by the individual listener. Only four of these songs, Wynonie Harris' "Good Rockin' Tonight," Louis Jordan's "Caldonia," Paul Williams' "The Hucklebuck," and Amos Milburn's "Chicken Shack Boogie" actually date back to the '40s. The other 18 selections, the bulk of this material, were released between 1950-1956, directly feeding into what became rock. Some of the artists here -- Fats Domino and Bill Haley -- would also later play rock & roll, while others -- Big Mama Thornton and Clyde McPhatter -- would introduce material that would later be recorded by Elvis Presley (for those unfamiliar with Thornton's energetic version of "Hound Dog," it's quite a revelation). Other fun, energetic cuts include Muddy Waters' "I'm Your Hoochie Coochie Man" and Ray Charles' "Hallelujah, I Love Her So." Roots of Rock provides a very nice hourlong snapshot of an era on the brink of a musical revolution. ~ Ronnie D. Lankford, Jr.