Even before he became the Red Headed Stranger, Willie Nelson was already a Nashville songwriting legend, providing Patsy Cline with her 1961 signature tune, “Crazy.” But as a fledgling performer in his own right, the clean-cut honky-tonker’s humble approach and conversational croon was increasingly at odds with mainstream country music’s tilt toward variety-show glitz. Upon joining the post-hippie roots-music radicals taking over the Austin scene (and swearing off barbers forevermore), the Texas-born Nelson became an icon of the ’70s outlaw-country movement, favoring a stripped-down style that could both evoke desert-highway vistas (“On the Road Again”) and initiate the most intimate of conversations (“Blue Eyes Crying in the Rain”). But Nelson’s brand of down-home simplicity shouldn’t be confused with dogmatic purism (he’s also no stranger to adult-contemporary crossovers, like his duet with Julio Iglesias, “To All the Girls I've Loved Before”). Rather, he’s always searching for the most direct route to the soul of a song, whether he’s elevating the country standard “Always on My Mind” to the realm of modern hymn, or bringing a wistful, lived-in wisdom to Great American Songbook perennials like “Georgia on My Mind.” In the 21st century, Nelson’s outlaw ethos has continued to manifest itself in all sorts of surprising ways: He’s become America’s most visible pro-marijuana activist and Snoop Dogg’s unlikeliest duet partner.