Over the span of his 30-plus-year career, Henry St. Claire Fredericks (known to everyone but his mama as Taj Mahal) has smuggled his suitcase full of blues across almost every musical border: rock, folk, jazz, pop, country, gospel, even calypso. And no matter which frame he chooses for his soulful songs, he’s never failed to fill the canvas with the world-weary voice (a thicker Ted Hawkins) and nimble guitar- and banjo-picking ability (vastly unheralded) that have kept him in bed with the critics—and just out of reach from the masses—for more than three decades. In Progress & In Motion 1965-1998 is a three-CD, 54-song mellow meltdown, 200 minutes of relaxation therapy sure to invigorate both the Taj-loyal and the Taj-curious. There isn’t much fat to be trimmed from this troika of discs, and the collection’s greatest triumphs come in rich, brilliant bursts: “Corrina,” “Checkin’ Up on My Baby,” and “Leaving Trunk,” all previously unreleased and redolent of a New Orleans flophouse, are culled from The Rolling Stones’ Rock and Roll Circus. Clean and tight (and very, very cool) offerings “Statesboro Blues” and “Bye & Bye” come courtesy of the Rising Sons, Taj’s modern-blues project with fellow guitar enigma Ry Cooder. Later in his career, the perpetually mourning guitar man settled on a consistent backing ensemble—the International Rhythm Band—and it’s with these diverse musicians (featuring Coral Reefer steel drummer Robert Greenidge and former Wailer keyboardist Earl “Wire” Lindo) that Taj created some of his most inventive music, including the swampy dirge “When I Feel the Sea Beneath My Soul” and the tropical bubble of “West Indian Revelation.”—Sean Daly