Considering that Lily and Madeleine Jurkiewicz of Indianapolis first came to public attention with YouTube videos of the sisters singing songs by Fleet Foxes and Adele, it shouldn’t surprise anyone that these teenagers rely on a similarly organic and low-key presentation for their self-titled debut album. Produced by Paul Mahern—with the songs cowritten between the sisters and Kenny Childers, a veteran singer/songwriter also from Indianapolis—Lily & Madeleine centers on the harmonies that defy all age and expectation. Their youth may gather the crowds, but the wrenching truth of “Disappearing Heart”—delivered with only vocals, electric piano, and a heavenly bell—will be what keeps the crowds’ attention. A gorgeous string section introduces the acoustic guitar–based “And Tonight,” which settles in for the type of chamber-folk popular in underground and some mainstream channels. Obvious comparisons to First Aid Kit, another acoustic sister act, should only firm up people’s perception that this sound is something almost trendy. Yet the handclaps of “I’ve Got Freedom” and the small band on “Come to Me” express an enduring, upbeat joy.