The organ in the Grote Kerk of Oosthuizen is one of the earliest playable organs in the Netherlands, but its origins are a mystery. The case, pipework, and the keyboard range (just over 3 octaves from F to high a”) are typical of the beginning of the 16th century, and the organ is often dated from the completion of the church building in 1521. Church archives contain a document from 1548 signed “Dierick Willemson coster ende orgel in oijsthuijsen” [Dierick Willemson, warden and organist in Oosthuizen] confirming that an organ existed at that date. During its restoration in 2002-2003, evidence was found that work was done by organbuilder Pieter Backer in the 17th century; possibly the sexquialter, not a stop found in 16th-century Dutch organs, dates from this work. The overall tone color of the organ has the fantastic strength and brilliance typical of Renaissance organ sound. Music includes selections from early German, Austrian, Polish, and Dutch tablatures including an epic intabulation of Josquin’s great Miserere, and one of Sweelinck’s great keyboard works, the Hexachord Fantasy.