|In the border regions of Thailand, Cambodia, Vietnam, Laos and Myanmar live nomadic "hill tribes" which subsist on agriculture. Various tribes have their own unique music and drums. The Thai Karen tribe has a long, slender drum similar to the Vietnamese Glawng Yao. The Thai Mien tribe uses an amazing wedge structure to tighten the heads of their drums. Vietnamese hilltribes have a drum that is similar to the Talking Drum of Nigeria except that one of its sides is conical while the other is spherical with a narrower opening for the head.