The comments from "a reader" (anonymous and pseudonymous reviews should be discouraged as a matter of Amazon.com policy; in non-life-or-death matters like critiques of musicology texts, surely the courage to sign your name is a prerequisite?) indicated a rip-off. In fact this publication turns out to be useful far beyond the confines of Dutch and Central European baroque topics. There can be no argument with complaints about unevenness. One section (the chapter on Austrian / South German baroque composers) is written with genuine panache; another (on Franck, his precursors, and his successors in the Gallo-Belgian romantic repertoire) is almost equally worthwhile; the advice on optimal practice methods for organists is uniformly well-judged; alas, all too many of the other sections read like - and probably were - extracts from humdrum doctoral dissertations.
The treatment of Spanish and Portuguese 16th- and 17th-century organ writing is, at least to the non-specialist writing this review, largely incomprehensible (and where not incomprehensible, is dubious: can it really be true that the "royal trumpet" stops which characterized Iberian organs, and which so well suit 17th-century Iberian "battle music", are an 18th-century invention?). A more obviously encyclopedic approach, such as Julie Anne Sadie employed when she edited Cambridge's COMPANION TO BAROQUE MUSIC, would have been superior to what we have here.
Still, here is one church organist who feels very grateful to this tome's staff-notation passages for having introduced him to valuable pieces by Teutons (the mid-17th-century's J. K. Kerll), Americans (the late-19th-century Dudley Buck), and Englishmen (somebody named Henry Smart, who apparently died in 1879), hitherto mere vaguely-contemplated names, or else, in Smart's case, not even that. Better to treat this COMPANION as a goad to the performer who seeks fresh and agreeable sheet music, rather than as a reference resource.