If you want a sample of what to expect from this quartet of Bulgarian expatriates living in the New York City area, do a YouTube search for “Nikolay Kolev, gadulka master” and prepare to have your mind blown. Kolev is a virtuoso on the gadulka — a traditional Bulgarian bowed stringed instrument that sounds something like a cross between a fiddle, balalaika and sitar — and when he lets loose, the sound recalls everything from fiddle reels and Celtic music to Mahavishnu Orchestra and Ravi Shankar, at least to Western ears. Along with Kolev, Bulgarika includes accordionist Velizar Tsonev and vocalists Donka Koleva and Maria Koleva, Nikolay’s wife and daughter. The concert/dance party is sponsored by Nashville International Folk Dancers, and the $10 admission charge includes refreshments. (Students get in free.) In addition to the Saturday concert, vocal and private instrumental lessons will be offered Sunday, so dust off that gadulka and head on down.