Maja Ratkje, half of this Norwegian duo, likes to cite fellow pigtail wearer Pippi Longstocking as an important influence. The children’s book heroine, she told an interviewer last December, “sleeps with her feet on the pillow. I try to turn certain conventions on their heads. Pippi is anarchistic and boundless in her ideas, but also has a great sense of fairness and justice. That’s a fine model.” Ratkje’s playfulness shouldn’t be construed to mean she’s not serious: the vocalist and composer is one of the most striking European experimental artists I’ve heard in the last few years. She first made her mark as a member of Spunk, an all-female improvised-music quartet whose two fine albums on the Rune Grammafon label veer crazily between noise, martial music, and giggling. Her own solo album Voice (Rune Grammafon), which uses her voice as the sole sound source, was one of the most arresting and original records of 2003. Working with the electronic duo Jazzkammer, she manipulated screams, gargles, chirps, and mumbles into songlike vignettes, industrial-strength racket, and ambient washes. In the same year she and fellow Spunk member Hild Sofie Tafjord formed Fe-Mail, whose debut, Syklubb Fra Haelvete (TV5), is a wild romp of unhinged, organic noise based on Ratkje’s staggering vocal prowess and Tafjord’s French horn manipulations, processed and mixed with live sampling and unidentifiable field recordings. The first part of their two-night engagement will reflect the processes used to make the album, while the second will be largely acoustic. These are their first U.S. appearances and the only ones on this trip. Friday and Saturday, February 27 and 28, 9 PM, 6Odum, 2116 W. Chicago; 773-227-3617 or 312-666-0795.