Formed in Germany after the fall of the Berlin Wall, 17 Hippies draw influences from Eastern European sounds that flooded the region at the time. Singing in German and English, the group plays original compositions, traditional songs, and pop covers. On the first disc released in the United States, Heimlich, the collective takes on instrumental moments and rock-inflected songs; the title track, an original written by accordionist Kiki (apparently, the band members were born without last names), features African thumb pianos for accompaniment. During live performances, however, 17 Hippies takes ownership of its sound. “Our audience in Berlin learned about these new, old sounds by listening to us,” Kiki said in an interview. “The ‘traddies’ hated us. Now in other parts of Europe they call it ‘Berlin style.’” 17 Hippies perform at 6 p.m. at the Kennedy Center’s Millennium Stage, 2700 F St. NW. Free. (202) 467-4600.