Everyone has visions of the apocalypse, and none of them are good. Christian conservatives fear it will happen along the lines of what is mapped out in the Book of Revelations. Liberals see it in less cataclysmic terms, envisioning man's violent nature and abuse of natural resources carried to the logical extremes. Regardless, both views lament humankind's selfish recklessness. Since 9/11, humankind's selfish recklessness has been the primary subject matter for underground hip-hop artists like Mr. Lif, who's seminal album I, Phantom ends with a song about the aftermath of nuclear war. Mr. Lif is one-third of the Perceptionists, whose recent album, Black Dialogue (Def Jux), articulates underground concerns about the future, offset by DJ Fakts One's catchy, old-school beats. Fellow Def Jux artist Akrobatik rounds out the trio of contemporaries from their days coming up in Boston's underground hip-hop scene. Get ready to party like it's the end of the world. Tickets $12.