Otis Redding sings "These Arms of Mine." Yearning, lovely, it becomes the B side of his first single. In five years, at 26, he'll die in a plane wreck, but not before defining Memphis soul, the bass- and horn-driven sound that, counterpointing Motown, sparked the '60s R&B explosion. Lavishly, the 95 studio, live and rare cuts of Otis! The Definitive Otis Redding capture his comet's trail.

Gospel and the rural sensibility behind blues and country music – the musical legacy of the South – is America's deepest source of aesthetic passion. And these two massive sets attest to the richness of that fundamental power.

From Nashville to Memphis reveals that reclaiming those roots meant Elvis' artistic resurrection. A key to Presley's greatness was a startling openness of spirit that fueled his stylistic range; yet that same malleability made him a substance-abusing drone in endless formula films. Pawn to Col. Tom Parker's managerial whims, Elvis struggled through the mire of his own success back to the music that created him. The RCA set's 130 songs chronicle his release.

In the early '60s, barred from recording better songs by Parker's mercenary publishing tactics, the King and his crack players could make even tripe palatable. But in 1964, with producer Felton Jarvis, Elvis began rebelling. "Down in the Alley," a hot blues number, and Bob Dylan's haunting "Tomorrow Is a Long Time" kindled fire; soon, Elvis freed himself to cover any song he chose – and he and Jarvis chose terrifically.

In 1969, Jarvis hired fresh musicians and fellow producer Chips Moman, co-architect of Memphis soul, to urge Elvis soulward, and they wrought wonders: "Suspicious Minds" displayed a voice alternately tighter and freer; Jerry Butler's "Only the Strong Survive" was truly hip R&B; and Mac Davis' "In the Ghetto" and Eddie Rabbitt's "Kentucky Rain" returned Elvis to his outsider's origins.

From Nashville to Memphis belies any notion that only the '50s Elvis was vital. From rockers ("Little Sister") to blues ("Long Black Limousine") to country ("It Hurts Me"), his command makes one judgment incontestable: Presley remains the finest singer rock & roll has produced.

Just as certainly, the four-CD Otis! proves Redding's preeminence among Southern soul singers. James Brown rivals him in heat, but Redding achieves a subtlety that has never seemed to engage Br