The question of the authenticity of many of Josquin’s works, along with the incomplete biography, is a major research challenge. While there has been great progress in the indexing of sources in the last 50 years, the question of the authenticity of many works is very controversial – not to mention the dating.

Josquin’s fame at the beginning of the 16th century, immensely promoted by the Petrucci prints, led to works not by Josquin also being attributed to him for marketing reasons.

The publisher Georg Forster, in the preface to his collection of motets published in 1540, said that he had heard a great personality say that Josquin had composed more since he was dead than when he was alive.

„Memini summum quendam virum dicere, Josquinum iam vita defunctum, plures cantilenas aedere, quam dum vita superstes esset.“ 

Georg Forster, Selectissimarum mutetarum … tomus primus, 1540

With the beginning of modern Josquin research in musicology, promoted above all by Wolfgang Osthoff’s meticulous monograph, a contrary trend then set in. The body of work attributed to Josquin has continued to shrink. Today, the editors of the New Josquin Edition assume that of 335 works attributed to Josquin, 143 can be classified as authentic, the authorship of 44 works is considered doubtful and for 135 works it is assumed that there has been a misattribution. 13 works could not be classified. Thus, Josquin’s authorship is doubted for more than half of all works. In the case of a large number of works, it has actually been possible to prove through sources that an attribution to other composers is more probable or even certain. A not insignificant part, however, is based merely on conjecture, either on the basis of the sources, on the basis of the compositional structure or for other reasons. Research is far from a uniform understanding of the work, to which the fact that even the few authentic compositions by Josquin are very diverse and varied has certainly contributed.

The editors of the New Josquin Edition, for example, have taken the rigid step of not publishing any spurious works in the edition.

Changing editors of the individual volumes and inconsistent criteria as to what is classified as “authentic”, “dubious” or “spurious” have resulted in a very heterogeneous picture. In my opinion, the three criteria mentioned are too schematic to get a good picture of the discussion. It is precisely here that I would like to give impulses for research and stimulate discussion with my own assessments. A website also offers the opportunity to disseminate current findings and revise assessments. Basically, I agree with David Fallows, who has called for a little more generosity in the classification of Josquin’s works.

That Smijers’s edition has only two-thirds of the full figure is partly attributable to subsequent discoveries, but more broadly it reflects con­siderable discrimination on his part — a discrimination continued by later researchers. But the pattern seems to suggest that Josquin is getting smaller and smaller; and it may just be time for a little more generosity. 

Fallows, Afterword: Thoughts for the Future, S. 571