"Trance blues" is Otis Taylor's catchphrase for his sixth record, Below the Fold. And he ought to know: After an up-and-down career that's spanned nearly four decades, he's refined his droning, modal blues and hypnotizing groan to a science. But that's not to imply that Below is short on soul. Although even less bombastic than its predecessor, Double V, the disc's subtlety more than delivers. In addition to his typically chilling historical accounts -- the Ludlow Massacre and the mistreatment of black soldiers during World War II are tackled here -- Taylor draws a veil of menace around him with "Mama's Got a Friend," a kind of sequel to Double V's "Mama's Selling Heroin." The tale of a lesbian affair his mother had while he was a child, "Mama's Got a Friend" eschews any statement about homosexuality and instead etches a tableau rife with the lush darkness of forbidden lust -- not to mention an eerie Oedipal undertow. Trance music might be all about slick beats and ambience, but in Otis Taylor's hands, trance blues is a thing of grit and gravity.