Children’s Hour guitarist Andy Bar admits that he was nervous about opening for Zwan at a sold-out Metro show in January. “I was scared that people were going to hate us and throw stuff at us,” he says in a voice barely above a whisper. It wasn’t just that he was more accustomed to playing in front of 30 or 40 people who knew his music than 1,000 who didn’t. The two acts seemed like an odd match: the unabashedly spare, fragile music Bar performs with Josephine Foster–who sings and plays guitar, ukulele, and harp–couldn’t be more unlike Billy Corgan’s overpowering anthems. But the crowd dug them, Foster says–“and I don’t understand why. You can’t understand how weird it is. Maybe it’s just a mob mentality, but no matter what we did at Metro people loved everything.”

Best of Chicago voting is live now. Vote for your favorites »

And the hot streak continues: in May they completed a six-week national tour with Zwan and the local Minty Fresh label issued their debut album, SOS JFK. Yet little more than a year ago they were ready to call it quits. “We were losing our enthusiasm and thinking about taking a break,” says Foster. She had plans to move to Portland, Oregon, and figured that if the Children’s Hour were to continue it would be as a collaboration by mail. So last April, when some friends in the rock band Kaspar Hauser asked the duo to open for them at the Prodigal Son, Foster says, “we were thinking it would be our last show for a while.”

Their music is quiet and gentle, and with no noisy guitars or rhythm section, Foster’s delicate, mannered vocals are left utterly exposed. Her opera training is evident–her precise enunciation is miles from a slurred, slangy rock delivery–and the duo’s whimsical yet dark melodies borrow more from traditional folk and Tin Pan Alley than from anything written in the last 30 years. Their beguiling austerity often suggests the work of 60s British folksingers like Shirley Collins and Anne Briggs, though Foster says her knowledge of folk music doesn’t go much deeper than Peter, Paul & Mary; indeed, the arrangements veer on occasion toward the folk-pop sound of Judy Collins.