William Chappell was an English writer on music, a partner in the London musical firms of Chappell & Co. and later, Cramer & Co. He suffered from writers' palsy for several years, but eventually recovered. He acted as honorary treasurer of the Ballad Society, for which he edited three volumes of theRoxburgh Ballads (London, 1869 c. 8vo). He was also an active member, and for a time treasurer, of the Camden Society. He gave most important assistance in the publication of Coussemaker's Scriptores de Musica (4 tom. Paris, 1863–76). The celebrated double canon, Sumer is icumen in, whose existence in a thirteenth-century manuscript is the most inexplicable phenomenon in the history of music, was long studied by Chappell; a facsimile in colours served as the frontispiece of his Popular Music of the Olden Time, and he finally succeeded in identifying the handwriting as the work of Johannes de Fornsete, and in showing that the writer died on 19 January 1239 or 1240.