The present research project focuses on a particularly salient, informative, and so far unexplored aspect of Islamic social movements in East Africa: their use of recordings of religious sermons in the Swahili language. Such recordings have been in use for about a quarter century. They are produced in various locations and religious contexts, traded throughout the region, and used for information as well as education and entertainment. Their topics range similarly widely, from differences between Islam and Christianity to Islam and science, education, family life and the status of women. Explicit references to politics and history are common, and oblique allusions even more so. The sermons therefore offer an unusual and privileged ‘nside view’of the Muslim revival in East Africa