by Bob TarteWith their extraordinary harmonic-whistle vocal techniques, Tuvans could well be the next sampling craze. From the Central Asian country reputedly settled by the descendants of Genghis Khan, folk group Shu-de accompany songs derived from shamanistic rituals with instruments whose sounds are as irreproducible as the vocals, including two-stringed igil fiddle and doshpuluur lute, a particularly articulate khomus jaw's harp, and a variety of drums and rattles. The wildness of these songs evokes centuries of accommodation to a demanding landscape, but tongue-twister Durgen Chugaa goes even further to verify prehistoric associations with a Popeye the Sailor cult.