"Volgend Buxtehude-jaar in 2037 of 2038. Gedachten bei een problem uit het Buxtehude-onderzoek." (The next Buxtehude year in 2037 or 2038? Thoughts concerning a problem in Buxtehude research). Het Orgel [Netherlands] 104, no. 1 (2008): 13-17.
Abstract in Dutch , in German, or in English
Complete Article (in German)

“A Meeting of Two Temperaments: Andreas Werckmeister and Arp Schnitger.”
In Music and Its Questions: Essays in Honor of Peter Williams, ed. by Thomas Donahue. Richmond, VA (USA): OHS Press, 2007: 75–99.

"Mehr als nur Fragezeichen." (More than just question marks)
Review (long version) of an edition of
Dieterich Buxtehude (?) (1637–1707): Nun freut euch, lieben Christen gmein. Choralfantasie für Orgel [in A-Dur]. Erstdruck mit zusätzlicher Fassung in G-Dur. ed. by Pieter Dirksen. Edition Breitkopf 8643. Wiesbaden: Breitkopf & Härtel, 2007.
A much abbreviated version of the previous review appeared at the same time in print in
Musik und Kirche 77, no. 6 (November/December 2007): 437.

"The Temperament of the Marquand Chapel Organ."
In Fanfare! A new organ for Yale University [Inauguration of the new Taylor & BoodyOrgan (op. 55) in the Marquand Chapel, Yale University]. New Haven/NJ, USA: Yale Institute of Sacred Music, 2007: 20–24 (part I), 37–44 (part II).

"Temperatur." ([Bach-] Temperament)
In Bach-Handbuch 4: Klavier- und Orgelmusik, ed. by Siegbert Rampe. Laaber: Laaber-Verlag, 2007): 623–640. = Reinmar Emans, Sven Hiemke, and Klaus Hofmann (eds.), vol. 4 (in 2 vols.: 4/1 and 4/2), Bach-Handbuch (7 vols.).
[Reviews of this article]

"Not quite just." [Book review of: Ross W. Duffin. How Equal Temperament Ruined Harmony and Why You Should Care.]
Early Music xxxv, no. 3 (August 2007): 452–454.

"Buxtehude med nya ögon – forskning, uppförandepraxis och bibliografi." (Buxtehude seen with fresh eyes: Research, performance practice, and bibliography).
Kyrkomusikernas Tidning (KMT) [Sweden], no. 8 (2007): 16–19.

"Stellwagen, Friedrich." and "Subsemitonium."
In Lexikon der Orgel. Orgelbau–Orgelspiel–Komponisten und ihre Interpreten, ed. by Matthias Geuting and Hermann J. Busch. Laaber: Laaber-Verlag, 2007: 739, and 752–754.

"Arp Schnitger."
In Neue Deutsche Biographie [NDB], vol. 23, ed. by Hans Günther Hockerts for the Historische Kommission bei der Bayerischen Akademie der Wissenschaften. Berlin: Duncker & Humblot, 2007: 326-328.

"De orgels van Buxtehude in de Marienkirche te Lübeck." (The Organs of Buxtehude in the Marienkirche in Lübeck)
Orgelkunst 30 [Belgium], no. 2 (2007): 52–61.
[Announcement in Flemish]
Summary (one pdf-file, 200 KB only) in French and in English

"Buxtehudes Orgeln in Lübeck." (Buxtehude's organs in Lübeck.)
In 'Ein fürtrefflicher Organist und Componist zu Lübeck'. Dieterich Buxtehude (1637-1707) [Katalog zur Ausstellung "Ein fürtrefflicher Organist und Componist zu Lübeck – Dieterich Buxtehude."Lübeck, Museum für Kunst und Kulturgeschichte (St.-Annen-Museum), May, and Utrecht], ed. by Dorothea Schröder. Lübeck: Verlag Dräger, 2007: 57–68 (fotos: 56, 69–83).

"Arp Schnitger, Organ Builder – Organ Itinerary."
In Google Earth Community.
[http://bbs.keyhole.com/ubb/showthreaded.php?Cat=&Number=789972&page=&vc=1&PHPSESSID=#Post789972]
09.02.2007.

(together with Mark Lindley) “Bach-Style Keyboard Tuning.”
Early Music xxxiv, no. 4 (November 2006): 613-623.
Click on this link to read the article online or on this link to download a pdf-file.
Click on this Bach-style keyboard tuning to see additional material, which will be published with the publication of the Early Music-article in print.
Click on this Errata and Corrigenda to Lindley/Ortgies: "Bach-style keyboard tuning".

"Das 'Bauwregister' 1652-1712' im Kirchenarchiv Stralsund St. Marien." (The 'Bauwregister 1652-1712' in the church archive of St. Mary's, Stralsund)
In Die Stellwagen-Orgel in Sankt Marien zu Stralsund. Eine Bestandsaufnahme, Chronik und Dokumentation, ed. by Martin Rost and Evangelische Kirchengemeinde Sankt Marien Stralsund.
Öhringen: Verlag Organum Buch, 2006: 13-55.

"Spekulation und Hypothese. Zur Diskussion um die Zellerfelder Orgeltabulaturen in Concerto Nr. 207/208. Eine Replik." (Speculation and Hypothesis. A contribution to the discussion about the Zellerfeld organ tablatures in Concerto no. 207/208. An answer.)
Concerto [Germany] no. 209, 2006: 22-24.
Further material:

"Friederich Stellwagen."
In Die Musik in Geschichte und Gegenwart, Personenteil. Vol. 15, ed. by Ludwig Finscher.
Kassel: Bärenreiter, 2006: col. 1411-1412.

"Über den Umbau der großen Orgel der Marienkirche zu Lübeck durch Friederich Stellwagen 1637-1641." (On Friederich Stellwagen's rebuilt of the large organ of St. Mary's in Lübeck in 1637-1641]).
In Orphei organi antiqui, Essays in Honor of Harald Vogel, ed. by Cleveland Johnson.
Seattle: Westfield Center, 2006: 313-335.
Click on this link to find Corrigenda and Errata Vogel-Festschrift.

“Schnitger.”
In Die Musik in Geschichte und Gegenwart, Personenteil. Vol. 14, ed. by Ludwig Finscher.
Kassel: Bärenreiter, 2005: col. 1529-1532.
Click on this link to find Corrigenda and Errata Schnitger MGG 2.

"Bartold Hering, Organist und Orgelbauer in Lübeck?" (Bartold Hering, organist and organ builder in Lübeck?).
Ars Organi [Germany] 52, no. 2 (2004): 70-74.

"Pipe Organs with Subsemitones, 1468-1721." and "Historical Organs with Subsemitones, 1468-1721: Appendix B."
In The Mathematical Theory of Tone Systems, ed. by Ján Haluska. New York: Marcel Dekker, 2004: 141-146, and 369-374.

(together with Frank van Wijk) "Reyne harmonie in Alkmaar. Stemming en temperatuur in Nederland in de 17de en 18de eeuw." (Pure harmony in Alkmaar. Tuning and temperament in the Netherlands in the seventeenth and eigtheenth Centuries).
Het Orgel [Netherlands] 99, no. 3 (2003): 12-36.
Abstract in Dutch or in English

"Subsemitones in organs built between 1468 and 1721. Introduction and commentary with an annotated catalog."
In GOArt Research Reports. Vol. 3, ed. by Sverker Jullander. Göteborg: Göteborg Organ Art Center, 2003: 11-74.

"Vallotti in het Groningerland. Over de restauratie van temperaturen." (Vallotti in the Dutch province of Groningen. On restoration of temperaments).
Het Orgel [Netherlands] 98, no. 5 (2002): 27-39, and Het Orgel [Netherlands] 99, no. 1 (2003): 28-35.
Abstract in Dutch or in English

"Ein Modell für Dresdens Frauenkirche: Eine Prozeßrekonstruktion der Silbermann-Orgel ist möglich!" (A model for the Frauenkirche in Dresden: A process reconstruction of the Silbermann organ is possible!).
http://frauenkirche-silbermann.de, 19.03.2001, revised 16.04.2001.
Fulltext available here: Silbermann 2001

"Organs with Split Keys or Added Keys fewer than 17 tones per octave (but more than 12)."
http://groups.yahoo.com/group/tuning/message/20120, 11.03.2001.

"Subsemitoetsen bij historische orgels tussen 1468 en 1721." (Split keys on historical organs between 1468 and 1721).
Het Orgel [Netherlands] 96, no. 6 (2000): 20-26.
Abstract in Dutch or in English
(Published originally in Swedish, "Subsemitoner i historiska orglar. En överblick över utvecklingen mellan 1468 och 1721." (Tidig Musik, no. 2, 2000: 26-31), and subsequently
in German, "Subsemitonien in historischen Orgeln. Ein Überblick über die Entwicklung zwischen 1468 und 1721." (Concerto 17, no. 156, 2000: 22-25).

(together with Martin Rost) "Hanseatiska fynd - inventering och dokumentation av Stellwagen-orgeln i St. Marien, Stralsund." (Hanseatic findings - stock taking and documentation of the Stellwagen organ in St. Mary's in Stralsund).
Orgelforum [Sweden] 22, no. 3 (2000): 118-123.
Published originally in German, "Hanseatische Funde. Bestandsaufnahme und Dokumentation der Stellwagen-Orgel in St. Marien zu Stralsund." Orgel International, no. 3, 2000: 180-184.
Abstract in English

"Beim Spielen singend denken. Im Gespräch: Siegbert Rampe." (Thinking of singing while playing. A conversation with Siegbert Rampe).
Concerto [Germany] 14, no. 122, (1997): 26-31.
Abstract in English

"Ze 1: An Autograph by Matthias Weckmann?"
In Proceedings of the Göteborg International Organ Academy 1994, ed. by Sverker Jullander and Hans Davidsson. Göteborg: Göteborgs universitet, 1995: 155-172.

"Die Wolfenbütteler Handschrift Der 128 Psalm a. 5. H. J. Br. Ein Autograph Matthias Weckmans?" (The manuscript 'Der 128 Psalm a. 5. H. J. Br.' An autograph by Matthias Weckman? ).
Concerto [Germany], no. 89, (December 1993/ January 1994): 22-31.
Abstract in English

"Matthias Weckman (1616-1674) und seine Autographe." (Matthias Weckman [1616-1674] and his autographical manuscripts.).
Concerto [Germany], no. 88, (November 1993): 30-31.
Abstract in English

"Neue Erkenntnisse zur Biographie Matthias Weckmans: Biographische Skizze und Zeittafel." (New findings about the biography of Matthias Weckman: A biographical sketch and chronological table).
In Proceedings of the Weckmann Symposium Göteborg 1991, ed. by Sverker Jullander.
Göteborg: Göteborgs Universitet, 1993: 1-24.

"Johann Sebastian Bachs 'Kunst der Fuge'. Bedeutung, Entstehung und klangliche Darstellung." (Johann Sebastian Bach's 'Art of Fugue'. Meaning, Origin and Performance).
In Dollart-Festival 1991 [Program book] ed. by Hermann Harms and Ibo Ortgies.
Aurich and Bunde: Verein für Orgel- und Musikkultur, 1991: 73-78
(includes translation into Dutch by Birgit Zeunert and Enno Schmidt: "[J. S. Bachs 'Kunst der Fuge'.] Betekenis, ontstaan en presentatie van de klanken." ).

"Von den alten Orgeln: Die Orgellandschaft Ostfrieslands. Eine Einführung." ('About the old organs'. The organ landscape of Ostfriesland (Northwest Germany). An introduction).
Concerto [Germany], no. VI/7-8 (1988): 12-18.