The liner notes pin it down to a single moment: a 1972 George McGovern rally in Austin’s Zilker Park, when new-to-town country singer WILLIE NELSON found himself on the bill with a lot of hippie rock bands. Unintimidated, Nelson forged ahead with the show, and a movement was born. This is likely an oversimplification, but there’s no doubt that the recordings that make up the three-disc THE COMPLETE ATLANTIC SESSIONS (Rhino)—with multiple bonus tracks and a full CD of live material recorded in Austin in 1974—help mark the genesis of the “outlaw country” scene. Atlantic producer Jerry Wexler freed Nelson from the Nashville cookie-cutter assembly line, and his albums Shotgun Willie and Phases and Stages still rank among his best work. Shotgun introduced “Stay All Night” and Johnny Bush’s “Whiskey River” to his repertoire (did Willie open his shows with a moment of silence before this?), while Phases proved to be one of country’s most successful concept records, detailing the dissolution of a love affair from both the female and male perspectives. Nelson, free to explore his muse, found a whole new audience in the bargain, and neither he nor his adopted hometown would ever be the same.