When talking about these teenage Barcelona punks, PJ Harvey’s name is always going to be the first one that comes up. That owes to frontwoman Jazz Rodriguez Bueno’s strident, gut-ripping howl, one of the few voices on the indie rock landscape that could merit such a comparison. But while Mourn may challenge Ms. Harvey’s elemental ferocity, they also play with a sloppily simple basement-hardcore urgency that’s just overwhelmingly endearing. That voice, combined with the band’s juvenile bash-it-out force, makes for a potent combination.