Peruvian folk songs from Susana Baca's new album Espiritu Vivo, released today, and the uncharacteristically acoustic sounds of Malian superstar Salif Keita's new album Moffou. Plus the strange world of John Cage's prepared pianos, music for harpsichord by Francois Couperin, the Psalms of David on an Ethiopian harp and Khaled's classic hit Aicha. Presented by Verity Sharp.