What happens when two lovelorn teenagers lock themselves in the basement with a couple of guitars? They conceive a 20-track album, burn 50 copies and go their separate ways. That could've been it for Baltimore's Metal Hearts, but Anar Badalov and Flora Wolpert-Checknoff persevered. After the seriously limited-edition Escapists, the pair added a few instruments to their palette and recruited Philly native Sam Leiber to record their Suicide Squeeze debut, Socialize. Badalov and Wolpert-Checknoff harmonize, overlap, volley and take turns murmuring the dark thoughts of predators and abandoned lovers, but their voices are muted under lush guitar, warm keys and skittery beats, with light touches of sad sax and moody cello. It's all very hushed, but the tension never lets up. "Gentleman's Spell" conjures the Afghan Whigs; "Mountain Song" filters a fighting couple through a thin wall and a thick pillow. Socialize is a bewitching start, but leaving the basement is a blessing for Metal Hearts. Live, Leiber augments the programmed beats with real drums, and the young singers sound louder and more confident as they spend more time in front of people. Let's see if they can keep it up when they go back down.