This paper draws on archival research in Iran and the United States, and an extensive use of digital tools to identify hundreds of instances of found soundtracks in Iranian popular cinema of the 1950s and 60s. It places the circulation of recorded sound by famous film composers like Henry Mancini, Bernard Hermann, Max Steiner, and Miklós Rózsa within a larger cultural history of the global life of midcentury design. The focus will be on the cinema industry in Iran, but the paper will draw some comparison to illustrative examples of this phenomenon in Egypt. The archival record indicates that growth of the Iranian film industry, partly out of a network of dubbing studios between 1948 and 1963, depended in large part on Hollywood distributors’ convenient blindness to the afterlives of their second-hand prints and their soundtracks. This industry was dynamic and prolific, but its legitimacy was always a source of worry due to the uncertain provenance of its source material. Focusing on the relay of second-hand film soundtracks, I argue that Iranian dubbing technology is central to understanding the creative volatility of cinema in the region. It counteracts the ideological fantasy pure circulation and simple influence. Technologies like magnetic sound striping (applied to second-hand positive prints) thrived in 1950s Iran precisely because these dubbing studios were largely unknown to producers of the original films until the early 1960s. The fact that this industrial-scale creative adaptation was foundational for a local industry that dubbed Hollywood mambo soundtracks over its noir thrillers, confounds any simple categorization of cooperation vs. competitive control over the local market.