Tonight, Malian desert band Imarhan Timbuktu performs at Bossa and on Saturday Tinariwen, the well-known Saharan desert combo, plays Sixth & I Historic Synagogue. While the appearance of guitar-toting Tuareg musicians with long, flowing robes and oft-covered faces isn't quite a novelty in D.C. anymore, thanks to a number of such groups touring here in recent years, it’s still far from mundane. Imarhan Timbuktu is visiting in support of its debut effort Akal Warled, while Tinariwen is promoting its February release Emmaar. I exchanged emails with Imarhan Timbuktu guitaristMohamed Issa Ag Oumar and Tinariwen bassist Ayedou Ag Leche