Jazz manouche, a contemporary musical genre originally inspired by the European Romani guitarist Django Reinhardt (1910–53), provides a fruitful case study for exploring the conceptual transformations and contradictions inherent within any “invented tradition.” This article’s point of departure is Reinhardt’s original composition “Django’s Tiger,” which today’s musicians typically perform with slightly different harmonies from those heard on the guitarist’s original 1946 recording. Consequently, an informant declared that the original version now “sounds wrong”—a considerable irony given that jazz manouche players typically regard Reinhardt’s own music with extraordinary reverence. The musical discrepancies in question, which stem from a mishearing, are indicative of a significant change in jazz manouche’s modes of transmission. Musicians once learned mainly by imitating Reinhardt’s recordings; “Django’s Tiger’s” customary chord changes are today based on his 1946 melodic improvisation rather than on its underlying harmonies. Since the 1990s, however, jazz manouche has increasingly spread via oral transmission and electronic media. Nonetheless, the history of “Django’ Tiger” suggests that the principal dissimilarities between today’s idiom and Reinhardt’s own music are not musical but ontological and epistemological: evanescent improvisations have been transmuted into fixed pieces and individual stylistic idiosyncrasies have become classicized orthodoxies. Especially revealing are the moments when these conflicting epistemologies have tangible musical consequences, such as when contemporary jazz manouche guitarist Adrien Moignard attempts to replicate the melody of Reinhardt’s original “Django’s Tiger” solo against the modified contemporary harmonies, an endeavor that has to be abruptly truncated to avoid yielding musical incoherence.