ABSTRACT
The hitherto accepted hypotheses are that Jacobus was probably born in or near the diocese of Liège and that he studied in Paris. The first is weak, the second strong. He seems to have had written access to the treatise of Lambertus, live if indirect access to the teachings and music of Franco, and probably direct personal access to Petrus de Cruce. Jacobus frequently makes it clear that he is citing from written treatises, but he strikingly does not do so for Petrus, whom he knows as a singer and composer, and it is not to Jacobus that we owe the knowledge that Petrus wrote a mensural treatise; hence the likelihood that his contact was personal and direct, whether or not he also knew a written treatise by Petrus. All this points to Jacobus being in Paris in the 1290s, late enough for him to know the motets with the semibreve groupings he reports (the two by Petrus de Cruce are in fascicle VII of Mo), but while Petrus was still in Paris. Because of the mentions of Liège, he is supposed to have returned to the place of his birth (!) to complete ‘in old age’ the final Books VI and VII. 1 It is indeed possible, but not a necessary assumption, that he wrote them there, with access to Liège practices and theory manuscripts; but that by no means permits us to assume that he originated there. His presumed Liège origins are then used in circular corroboration of other aspects of the Liège hypothesis. In the preceding chapters we have eliminated Tu, the motet citations, and the chants as compelling reasons for a Liège origin. This leaves the testimony of his direct knowledge of liturgical practices, and of the two liégeois theory manuscripts, though acquaintance with both of those could have been achieved on a visit. Or, arguably, he could have had access to a now-lost close relative of those theory manuscripts in Paris or elsewhere. Indeed there are links to Liège, but not uniquely to Liège; that connection has led to neglect of clues to other places which could point to a wider frame of reference. By the later stages of his great project, Jacobus also had contact with the innovations and treatises of the early 1320s (by Muris and probably Vitry), pointing to a second period in Paris, or at least to his access to written texts of ars nova theory.
