Despite her instrumental prowess—classically trained on violin and viola and self-taught on guitar and charango—Ólöf Arnalds’ calling card is her crystalline voice. She was already fairly well-known in Iceland’s music scene by the time her debut solo release, Við Og Við (stream it below), arrived in 2007, going on to win Record of the Year and Best Alternative Album at the Icelandic Music Awards. When the LP came out in the U.S. three years later, Paste declared, “Earnest, heartfelt declarations of love are a welcome change from the too-cool posturing of so much of today’s popular music. Familial affection will never go out of style; neither will deftly plucked stringed instruments, subtle orchestral swells and a songbird lilt this impossibly lovely.” The singer-songwriter has since toured with the likes of Björk, Jonathan Richman and Dirty Projectors and released several more EPs and full-players, including 2014’s Palme (stream it below). It’s “as pure as powdered snow, yet bubbling over with fairy mischief,” proclaimed AllMusic. Arnalds (above, performing an Icelandic version of “Turtledove” for the Line of Best Fit and, below, covering “Mr. Tambourine Man”) “is a weaver of ephemera, and with each new collection of music, she both defines herself and furthers her own mythology, a mythology that’s wholly intertwined with the lore of her Nordic homeland.” See her play Mercury Lounge tomorrow night. Alternative-folk trio Cold Weather Company open the show.