Frequently in his late vocal music—in all genres large and small, sacred and secular—Haydn employs chromatic completion. By which is meant that there are structural units, cycles of musical time, defined within by the gradual unfolding of all twelve members of the chromatic aggregate. What is remarkable is that the twelfth and “completing” tone arrives in a manner that has clear structural and expressive significance. So much so, one is led to the conclusion that these cycles are hardly accidental; but, instead, were central to the composer’s artistic designs.
"The Technique of Chromatic Completion in Haydn's Late Masses,"
HAYDN: The Online Journal of the Haydn Society of North America: Vol. 1
, Article 1.
Available at: https://remix.berklee.edu/haydn-journal/vol1/iss1/1