Rap-rock has taken its lumps in recent years and has certainly slipped further back underground from its heyday of dominance in the late 1990s and early 2000s. Those who miss it, however, should be heartened by Hollywood Undead's second studio set, "American Tragedy," a tight mash-up between contemporary sonics and old-school aesthetic. In fact, new "clean" vocalist Danny Murillo's keening upper register hews so close to Chester Bennington's that this may be a salve for fans dismayed by the stylistic left turn of Linkin Park's latest album, "A Thousand Suns." There's plenty of metallic hip-hop stomp in such tracks as "Been to Hell," "Glory," "Lights Out," "Tendencies" and "Levitate," while "Comin' In Hot" and "Gangsta Sexy" are booze-and-booty-fueled party anthems. But Hollywood Undead broadens its parameters this time, too, pulling out acoustic guitars for the decidedly pop-friendly "Coming Back Down" and the Sublime-like "Bullet"-lighter- gauge counterpoints to an otherwise heavy affair.