In the chaos of Mahikeng’s biggest taxi rank, the distinct voice of a woman announcing the availability of Botswana’s pula stands out. Mmamoreki, as she’s known, sits behind a counter of old fruit boxes. The counter also serves as a front to what is effectively a foreign exchange office that has come to be just as important as a cultural office.  On top of the counter is a variety of products, from sweets to home-wrapped chips. But it is a stack of CDs that draws the most attention. On top of these is Botswana’s legendary traditional music group Machesa’s critically…