Abstract
This article illuminates the modern concept of the triadic root by analyzing that concept and explaining how the English-speaking world came to refer to it with the term root. To do so, it begins by identifying five subconcepts on which theorists have drawn when explaining and applying the root concept in their treatises. The article then addresses the origin of the term root in English-language theory, noting that the term first emerged only in 1806, far later than its modern-day ubiquity would suggest. This late emergence is explained as a side effect of the idiosyncratic state of triadic theorizing in eighteenth-century Britain. The author advances a new interpretation that, as a result of the overtone-based preoccupations of erudite authors and the particular emphases of thoroughbass teachers, British theorists did not use a fully realized triadic theory until much later than has been supposed. The conclusion of the article traces the process by which the term root gained ascendancy in English texts and considers how this history fits into larger trends of thoroughbass and harmony instruction.