You can read a hundred histories of early rock and roll, and still not understand exactly how the spark of a century was generated. There were so many factors that all came together at once in the 1950s to birth what we now know as the rock and roll era, it just seems inevitable. History can be messy, but is there any way to tell the story concisely?

James A. Cosby does a more than creditable job of that in his new book Devil's Music, Holy Rollers and Hillbillies. The title summarizes Cosby's argument regarding the three main drivers of the rock and roll explosion.

"Devil's music" is the amped-up, sexualized rhythm and blues of the late '40s and early '50s. The "holy rollers" would be Pentacostals: practitioners of a highly theatrical, uncommonly integrated brand of American Christianity. Finally, the "hillbillies" are the rural whites who codified the era's country music.

Love him or hate him, Cosby argues, Elvis Presley was at the convergence of all of those worlds — the right talent at the right time, with of course the right skin color. While Cosby recognizes Ike Turner's "Rocket 88" as the surest claimant to "first rock and roll song," he says it was Presley's version of "That's All Right Mama" that "solidified the sound" of rock and roll in the popular imagination.

Though it's a relatively short book for such a vast subject, Cosby's tome is notable for its careful attention to cultural context. He devotes a full chapter to popular culture in the 1950s, and his discussion of the roots of black music stretches from the 17th century to the present. That's important, because rock and roll was never just a sound: it was an way of thinking about the world.

No one understood that better than Chuck Berry, who Cosby calls "rock's first great composer." Berry didn't stumble into his sound like Presley did; the St. Louis singer-songwriter completely understood the dynamics of the new genre, and brilliantly played to its burgeoning audience. In the process, he "gave rock and roll its original voice and attitude, capturing the spirit of American youth in the 1950s, both black and white."

A challenge for any writer tackling this era is to describe the trajectory of rock and roll in the pre-Civil-Rights era — when important progress was made amid profound pain. The music was fundamentally premised on the conjoining of white and black musical worlds, but segregation was still a fact of life, particularly in the music's southern homeland.

Cosby captures the contradictions of Presley's life and career in a sensitive discussion: a poor white, Elvis couldn't have done what he did without a true feeling for African-American music, and consistently credited his black influences. "A lot of people seem to think I started this business," Presley told Jet in 1957, "but rock and roll was here a long time before I came along. Nobody can sing that kind of music like colored people."

Still, he was a white man who found enormous commercial success with a fundamentally black musical language, and many African-Americans viewed him with a suspicion that will always be part of his legacy.

There are other greats who come into this story. There's Hank Williams, who turned country from hillbilly music (string bands emphasizing traditional tunes) into cowboy music (lonely singer-songwriters with guitars). There are Sam Phillips and Dewey Phillips, the latter a radio DJ who Cosby argues is "vastly overlooked" for proving that black music could appeal to a mixed-race audience. There's Robert Johnson, whose supposedly Devil-given talent was actually a sophisticated blend of several music styles. There's Sister Rosetta Thorpe, who brought the fire as an electric guitarist accompanying gospel music. There's Minnesota's own Eddie Cochran, and there are so many more.

Devil's Music, Holy Rollers and Hillbillies serves as a readable and informative guide to them all, and chapter after chapter, it will have you reaching for your record player.