"I can't even crack a frown since the blues slipped out of town," sings Keb' Mo' on "Prosperity Blues," with a patented big wide grin you can practically hear. It's a witty and accurate assessment of his approach to the often lowdown genre. Even on the album's title track, where Mo's tough National steel slide playing is most prominent, he's concerned with the daunting amount of coffee choices at his local java emporium. Call it the middle-class blues then, as Mo' wraps his grits-and-honey voice around another set of gently rolling, melodic, and warm compositions. Similar to, say, James Taylor, he spins beautifully crafted, meticulously produced, uncluttered roots-influenced music that is no less satisfying because of its smooth qualities. Traces of gospel, folk, and even bluegrass sprinkle these pop-oriented tunes, and while most of the edges here are sanded off--nobody will mistake him for Howlin' Wolf--Mo's cushy voice and charm create another winning entry in his catalog. Sophisticated and burnished,