A mash-up of classic rock grooves, '70s metal sludge, and splatter-paint distortion and discord, Dinosaur Jr.'s second album is as sticky and enveloping as the aptly named "Tarpit." While he was one of the first great guitarists in indie rock (dig the muscular solo on "Raisans"), J. Mascis is a beautifully lousy singer. But that's what lends resonance to pleas like "I'm waiting/Please come back" on "SludgeFeast." He's the slacker you can't help but fall for.