Daniel N. Leeson was bass clarinetist with the San Jose Symphony orchestra for twenty years and is an award-winning writer of nonfiction, including articles dealing with Mozart, published in the Mozart Jahrbuch, Music and Letters, The Instrumentalist, The Musical Times, Musical America, MadAminA, the International Journal of Musicology, Eighteenth Century Music, and The Newsletter of the Mozart Society of America. In addition, he has written program notes for the London Proms concerts, the San Francisco Symphony, San Francisco's Midsummer Mozart Festival, and others. He is an editor of the Neue Mozart Ausgabe's 120 volumes of Mozart's music, and is an officer of the Mozart Society of America.
Leeson has been an invited speaker at the Salzburg Mozarteum as part of the International Congress of Mozart scholars; at the Chautauqua Institute; the Nevada Mozart Festival; and the California Mozart Society in Carmel/Monterey. In 1992 and 1993, he was a faculty member of the Mozart Opera Studies Institute (San Francisco State University and California State University, Fresno).
Leeson's fiction work, The Mozart Forgeries, was published in 2004.