Kenny Wayne Shepherd is no longer a young hotshot guitar-slinger. But closing in on 40, he’s showing that he and his band know exactly how to keep the blues a popular genre without turning to gimmicks or pop refreshes; they play as hard and intensely as the genre allows. This wasn’t always true for Shep, who in the past looked toward contemporary productions to help him break in new crowds. This time around he’s learned from past mistakes. A number of guests make their presence felt on his band’s seventh studio album, Goin’ Home. The Rebirth Brass Band give Freddie King’s “Palace of the King” a defiant kick. Warren Haynes adds heat to Albert King’s “Breakin’ Up Somebody’s Home.” Robert Randolph does his part on Muddy Waters’ “Still a Fool.” The band themselves pull off Magic Sam’s “Everything’s Gonna Be Alright” with true ferocity. By playing the songs of his main influences, Shepherd finds the holy grail of the electric blues. He energizes others, too. Joe Walsh hasn’t sounded this inspired in years, playing Willie Dixon’s “I Love the Life I Live” with The Fabulous Thunderbirds’ Kim Wilson nailing it on harmonica.