The original line on Gary Clark, Jr. was that the young Texas guitarist was supposed to be the future of the blues, having been mentored by Jimmie Vaughan and Eric Clapton, but as his star rises, Clark has made it increasingly clear that his creative ambitions run a lot deeper than being the next hotshot guitar slinger. On his major-label debut, 2012's Blak and Blu, Clark demonstrated he isn't interested in following the path of blues traditionalists, and while there's plenty of great guitar work on 2015's The Story of Sonny Boy Slim, this is by no means a conventional blues album. Rather, The Story of Sonny Boy Slim is a thoughtful and passionate amalgam of African-American music past and present, and the blues is one of many crucial ingredients in the formula along with R&B, soul, rock & roll, funk, gospel, and hip-hop (the cyclical drum and guitar patterns that dominate many tracks demonstrate in themselves that the aural dividing line between blues and hip-hop isn't as wide as some like to imagine). Clark's guitar work is outstanding throughout, but his style is more about expressive layers of sound than tasty licks, and this isn't a guitar album so much as an album that features a lot of guitar amidst a rich variety of ingredients, which may not please folks waiting for a new Stevie Ray Vaughan. And Clark has more on his mind than the accepted templates of electric blues; the raw, swaggering R&B throb of "Grinder" accompanies a meditation on poverty and materialism, the acoustic street-corner jam of "Church" tells the tale of a man torn by love and loyalty, "Hold On" marries taut soul figures to bitter, heartsick observations on the struggles of the African-American community ("Seems like new news is the old news from a different angle/Another mother on TV crying 'cause her boy didn't make it"), "Can't Sleep" evokes Chic as Clark sings of falling for the wrong woman, and the rough landscape of guitars and percussion on "Wings" complements a tale of struggle that might not out be out of place on There's a Riot Goin' On. And the most explicitly bluesy cut on the album, "Shake," is a raw slice of juke joint jump that evokes Hound Dog Taylor more than the polished showmen Clark was expected to follow onto the blues circuit. Blues may be at the root of nearly everything on The Story of Sonny Boy Slim, but it's not the sum total of Clark's musical world-view, and if he's abdicated the position of the future of the blues, this music declares that Clark is one artist who will see to it that the blues does indeed have a future, which is what makes him important and Sonny Boy Slim a serious leap forward from Blak and Blu.