young Presley, the resplendent Hillbilly Cat, was a vote for the boundless possibility and the sexy threat presented by rock & roll – the dream of climbing from the two-room shack to the mansion on the hill, playing by your own rules. It is this piece of the Elvis myth that is documented in RCA's monumental five-CD box The King of Rock 'n' Roll: The Complete '50's Masters, released just weeks before the fifteenth anniversary of Presley's death.

What actually comes through most strongly in this set, however, is a refutation of the most common perception of the early Elvis: that he was a simple country hick magically blessed with a golden voice, a musical idiot savant who naturally and effortlessly came up with a new sound that changed the world. Over the course of these 140 tracks (every recording from "My Happiness," the 1953 acetate cut in Memphis's Sun Studio as a birthday present for his mother, until his 1958 army induction, with fourteen previously unreleased cuts), Presley the singer emerges as a workhorse, a student – finally, unarguably, an artist.

In the six years covered, one can hear Elvis's ever-confident singing become increasingly honed and refined, for better and for worse. Presented with generally decent, challenging material throughout this era, his singing reaches masterful heights in tracks like the 1957 Leiber and Stoller ballad "Don't" until it stands poised at the brink of collapsing into the stiff mannerisms that would sink the worst of his insufferable soundtracks and his tossed-off later work.

The most revelatory cut in The Complete '50's Masters is the first release of "That's When Your Heartaches Begin," the flip side of the "My Happiness" acetate. When "My Happiness" finally surfaced two years ago, it proved a surprisingly assured, traditional reading, if not exactly the Grail – the work of a young man who genuinely idolized Dean Martin. "Heartaches" is something else entirely; from the vocal swoops and slurs to the melodramatic bel canto spoken verses, this is the blueprint for numerous classic performances that followed. This eighteen-year-old is immediately identifiable as the Elvis we know, the one who announced on his arrival at the Sun Studio that "I don't sound like nobody."

These two songs eventually earned Presley the chance to return to Sun, and the resultant 1954 and '55 sessions, of course, are probably th