The three Finnish women in V … rttin … , along with a six-piece backing band, perform traditional songs and chants from Scandinavian and Baltic countries. They add driving, modern rhythms on both old and new instruments, including the violin, accordion, jouhikko (a three-stringed bowed lyre), cumbus tambur (a Turkish long-necked lute), bouzouki (an eight-stringed lute), drums and kantele (a kind of Finnish zither considered the country’s national instrument). The result is a sound that is at once earthy and otherworldly, rooted in the soil of the past yet soaring into the planetary ether. The backing music is always solid, but it is the eerie, off-kilter, nasal harmonies of the singers that distinguishes this group. Founded in the 1980s in Raakkyla, Finland, V … rttin … was, at one point, a full-scale ensemble of 21 female singers. Talk about grrrl power! They’ve got a smaller vocal lineup now, but can still provide the sharp, shocking sting of these haunting traditional harmonies as they seek out new innovations and extensions of their sound. 8 p.m. Tickets are $20; $10 for students. Note Duke’s new parking policies: $2 per hour in the freshly-opened parking garage by the Bryan Student Center. You can no longer park for free in the Biology Building lot off Science Drive (boo!). For more information, call 919-684-4444 or visit