A bass-free bluesy duo lumped in with The White Stripes last year, Akron, Ohio’s Black Keys bring real purpose and energy to their lo-fi, refracting Otis through Led Zep with more than a hint of Hendrix. Actually, they’re more spiritual heirs to the Gun Club, Dan Auerbach hollering with hunger and hurt. It’s terrific, lively fun?soulful, even?as long as nobody tries to tell you there’s something radical about it.