13. “The question of its authenticity has plagued the Requiem from the first,” writes Christoph Wolff: “No wonder, then, that Mozart’s Requiem became the first work to be subjected in our modern sense to a most rigorous scrutiny regarding both sources and style.” See his review of two facsimile editions of the famous manuscript, 19th Century Music 15/2 (Fall 1991):162–65, esp. 165, for a succinct summary of the matter. For more, see his subsequent monograph on the work: Mozart’s Requiem: Historical and Analytical Studies, Documents, and Score (Berkeley: University of California Press, 1994).