Nobody expected Lily & Madeleine’s first original song, “In the Middle,” to rack up a quarter of a million YouTube views. The Internet is obsessed with what’s new and what’s next, the fads and memes of viral culture, and so it would have to seem a little incongruous for social networks and content aggregators to embrace gimmick-free, black-and-white footage of an unplugged duo crooning a bittersweet and understated melody. But there’s something inherently incongruous about the music of Lily and Madeleine Jurkiewicz, a pair of slight teenagers with singing voices this assured and worldly. Their first EP, The Weight of the Globe, sounds like something out of another age, not the work of a pair of sisters born less than two decades ago. No wonder that, on the strength of their viral video performances, Lily & Madeleine managed to sell out the first two live shows of their career, and enlist the help of Asthmatic Kitty Records. Their songs are the product of two distinct musical personalities. Madeleine, the older sister with a light, smooth singing style, leans towards folkier, singer-songwriter fare; Lily helps lean the duo towards its gentle rock edge, and has a dark, earthy voice to match. But their voices blend into seamless close harmonies, created with the natural ease that could only come from a pair of musicians who have known each other literally their entire lives.