This article examines the history of timbre in Qur’anic recitation, focusing on the intersection of the interior, conceptual, rule-based space of the mouth and the exterior, physical, highly variable architecture of mosques. In both cases, timbre plays a critical role in making Qur’anic recitation recognizable, even to untrained ears, and even if—especially in the case of mosques—that predominant, stereotyped setting is not necessarily representative of the tradition more broadly. The article examines the tension between Qur’an as fixed text and as recitation (qur’ān) and the challenges of reconciling these two notions of Qur’an into a definitive, unitary whole, that proved elusive in the early centuries of Islam, precisely on grounds of timbral, phonetic, and dialectal questions. At the same time, the elaborate design of rules for proper recitation has been so fully developed over the last millennium that it has become a kind of cultural technique, a rule-based algorithm that imposes on human performers a set of media-like operations. Indeed, recent computer science and engineering have fully embraced the algorithmicizing of vocality and timbre in recitation to the point of creating a number of software platforms designed to reproduce or assess the proper application of these rules. In all these different trajectories—mouth, mosque, and media—the alphabetics of the Qur’an play a central role in transducing a sacred text into the contingencies of the material world.