The crawling, surreal Houston rap style known as “screw” has gained a nationwide profile, with representatives like Paul Wall taking it way beyond Texas. He claims to be a fan above all, but behind his modesty is a convincing spitter with a stack of tracks that sound laden with doom even as he and his crew are simply bragging about their cash or celebrating their syrup habits. “Sittin’ Sidewayz,” Wall’s breakout single, is a spectral, echoy track that makes partying sound as threatening as an escaped prisoner. Similarly, “Trill” wouldn’t sound out of place in a horror movie; its placement in the sequence helps demonstrate a seeming intent to continually slow the album’s tempo until it has no choice to pick up (a little) speed with the Kanye West-produced “Drive Slow.”