If you’re performing folk music from the indigenous people of the northern Nordic area, you must be joiking. The Sámi have lived in the upper reaches of Norway, Finland, Sweden, and Russia’s Kola Peninsula for around 5,000 years, but Christian missionaries in the late 1600s tried to put a stake in their shamanistic religion, which included wordless, chantlike hymns that have no fixed beginnings or endings. That’s because joiks aren’t about things or people; they are meant to represent and reflect the essence of their subjects, like sonic holograms. Despite Sámi cultural repression, joiks never went away entirely, and young singers such as the Gaup Sisters are introducing new audiences to the tradition, which sounds analogous to Native American intonations: droning, haunting, and deeply beautiful. Hailing from Kautokeino in northern Norway, the Gaup Sisters—Inger Biret, Risten Anine, and Sara Marielle—primarily perform traditional joiking, which means the songs are unaccompanied, but Sara also sings in Adjágas, a group that mixes ancient vocal stylings with modern instruments. Joiking is a living tradition—no joke.

The Gaup Sisters perform at 6 p.m. at the Kennedy Center’s Millennium Stage, 2700 F St. NW. Free. (202) 467-4600. kennedy-center.org.