Moctar and his band (except for the bass player) are Tuareg people from the Niger section of the Sahara desert, and they play a kind of electric guitar music known as “desert blues.” Tinariwen are best known to Americans, though there are at least a dozen acts making killer records. Figure loop and repeat and chord changes are infrequent. You just plug in, rev it up—but not too much—and go. Mdou Moctar goes and goes.