In discourse on the topic, the question of what constitutes a musical ‘borrowing’, if raised at all, is usually restricted in scope and framed as one of terminology – that is, of determining the right term to characterise a particular borrowing act. In this way has arisen a welter of terms that, however expressive of nuance, have precluded evaluation of the phenomenon as such. This is in part a consequence of general disregard for the fact that to conceive of musical borrowing entails correlative concepts, all of which precondition it, yet none self-evidently. Further preclusive of clarity, the musico-analytic lens of borrowing is typically invoked only in counterpoint to a quintessentially Western aesthetic category of composition ex nihilo. As a consequence, the fundamental role played by borrowing in musical domains situated at the periphery of the Western art music tradition, specifically pre-modern polyphony and twentieth-century musique concrète, has been overlooked. This article seeks to bridge such lacunae in our understanding of musical borrowing via phenomenological investigation into its conceptual and historical foundations. A more comprehensive evaluation of musical borrowing, one capable of accounting for its diverse instantiations while simultaneously disclosing what makes all of them ‘borrowings’ in the first place, is thereby attainable.