Book excerpt: Remarkable treasury includes nearly all of early Dutch composer's difficult-to-find organ and keyboard works, reproduced from a clearly-printed, reliable 1943 edition. Includes chorale variations; toccatas and fantasias; variations on secular, dance tunes. Also 3 incomplete and/or modified works, and an authentic fantasia by John Bull, based on a now-lost Sweelinck fugue. New Publisher's Note. Contents with incipits.