- Peter Williams
(b ?Hennaard, Friesland, c1650; d Tzum, c1725). Dutch writer on music, organist and schoolmaster. While mysteries remain about Douwes’s biography and publications, there is no doubt that his little Grondig ondersoek (Franeker, 1699/R) is one of the most important sources of information for historians and makers of keyboard instruments, offering unique details on the scaling of the clavichord and virginals. It also discusses the trumpet marine and ‘noardske Balke’ (noordsche balk). His general musical education came from such Dutch authors as J.A. Ban, but his data on instruments (useful, like his discussion of musical intervals, to remote Friesian organists) were more empirical and, though based on an uncertain unit of measurement, much more practical than those of any European theorist of his period. His treatise is concerned with the notes (toonen) of music: how to tune them, how to use them harmonically and how to produce them on different instruments. It does not seem to have been widely known at the time....