By joining the ISO, you can keep yourself informed about worldwide developments and maintain contact with colleagues in many different countries. Membership of the ISO also signifies your support for international friendship, good standards, open communication and the free exchange of ideas throughout your profession. 

The ISO Journal

The ISO Journal is published three time a year and includes various articles submitted by members and occasionally others, describing instruments which have been built, re-built or restored, as well as related subjects such as scaling, tuning methods and the history of the organ. The ISO Journal is published in three languages, English, French and German so that all of our members are able to share the information.

The Biannual Congress

The biannual congresses of the ISO are the high point of the society's calendar. Each time we meet in a different country and are shewn the instruments of that country, learn of the history of the instruments and organbuilding and visit member's workshops.

The Workshops

These are smaller than congresses, generally numbering up to 30 participants, where a particular theme is dealt with in depth. They can comprise lectures, visits and practical instruction in whatever theme is being dealt with and generally last 3 to 4 days.


The ISO provides a closed email-based forum for its members only, where any member can pose questions to all the other members for consideration and assistance. It is most unusual for a question to go unanswered by somebody who has the experience and knowledge sought, and is given freely and most helpfully.

Apprentice Exchange

Our young organbuilders are also our future for organbuilding. The ISO encourages and can assist in the exchange of apprentices between organbuilding firms to afford these up and coming organbuilder the possibility of gaining experience outside the confines of the firm they are apprenticed with.

World Wide Representation of Organbuilders' Interests

Occasionally, issues arise which may have an impact on organbuilding the world over, or even in a particular region of the world. One of the objects of the ISO is to keep an eye on such developments and to take an active role in addressing any issues which might arise and be of concern to the continuation of our craft.

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After apprenticeship and working in various companies in Switzerland, England, France an Japan, Peter set up is own workshop in Rheinfelden, Switzerland in 2004. He is fascinated by the unique combination in our profession, where technical, musical and aesthetic skills are needed. He sees the ISO as a great opportunity to develop the international exchange and knowledge in organ building.

Peter Meier
2nd ISO vice president and secretary

In 1986 he started his apprenticeship at the Sueddeutsche Orgelpfeifenfabrik Roland Killinger to become a pipe maker with educational at the Oscar Walcker Schule in Ludwigsburg, Germany. In 1989 he worked at the Killinger - reed making and voicing. Since 1995 workshop manager at Killinger. 2002 - CEO of KILLINGER PFEIFEN FREIBERG

Christoph Ulmer
Board member

Andrew joined Harrison & Harrison as an apprentice in 1994. At the age of 22 he became London Tuner. In 2012 Andrew has been responsible for the musical success of many projects, including the Royal Festival Hall and King’s College, Cambridge. In addition to his work at H & H, Andrew is an accomplished organist and choir trainer, currently holding the posts of Director of Music at St Michael & All Angels, Croydon, and Director of the chamber choir, Amici Coro.

Andrew Scott
1st vice president

Catarina Grönlund fourth generation of organbuilders in the Grönlund family and Company. She has since 1980 worked as organbuilder. Now she is managing director and also works with design, technical drawing, service and in the workshop.

Catarina Gronlund
Board member

Studied « history of art and musicology » (master thesis: “La facture d’orgues liégeoise au XVIII siècle: la dynastie des Le Picard et Robustelly” Musical studies at the Conservatoire Royal de Musique de Liège. Working since 1984 in the family business. Publisher of the ISO Journal and ISO Treasurer since 2006

Guido Schumacher
ISO treasurer

After studies in Sacred Music and training as an organ builder, Matthias Wirth worked as a voicer for the companies Rieger (Schwarzach/Austria) and Seifert (Kevelaer/Germany). Since 2018 he has been working as a freelance voicer for various companies in Europe. He also specialises in marketing, strategy and communication for small handcraft businesses, non-profit organisations and local politics. He loves to explore the big lines and the details in organ building and music. Therefore, it is a special pleasure for him to bring all these skills together in the activity as editor of the ISO Journal.

Matthias Wirth
ISO Journal Editor

Didier Grassins interest in organbulding began in the shadow of the famous clicquot organ of Poitiers, France, his native town. His professional path took him through several years as freelance designer, working for many major european and american firms before joining casavant frères for eight years. In 2011, he joined the Noack Organ Co. in Georgetown, MA, taking its leadership in 2015 at the retirement of Fritz Noack.

Didier Grassin.
ISO president

Markus began his apprenticeship at Rieger-Orgelbau in 1990 and worked there as an organ builder and intonator until 2010. He then became self-employed as a freelance intonator and worked for various companies. Since 2015 he has been the freelance intonator at the Wegscheider organ building workshop in Dresden. Markus has been a member of ISO since 2016.

Markus Zoitl
Board Member

After graduating as an architect and practicing the profession for several years in the UK, Michela Ruffatti joined Fratelli Ruffatti organbuilders, the family firm based in Padova, Italy, in 2004. Along with the principals of the firm, she works as both technical and visual designer, and she supervises the construction and installations of new organs and the restoration of historical organs. She is currently president of the Italian Association of Organbuilders.

Michela Ruffatti
Board member

Alongside viola and organ studies, Thomas first trained as a cabinet maker in Lausanne’s Technical School before starting an organ building apprenticeship with La Manufacture d’orgues St-Martin, also in Switzerland. After that, he had the opportunity to be involved in several projects mainly in England but also in Italy, New Zealand, Japan and of course Switzerland, where he has worked for Orgelbau Goll Luzern since 2015. Throughout his career, he has had the privilege to work on a variety of jobs, ranging from woodwork, CNC machining, to organ maintenance and tonal finishing, the latter now being his main fields.

Thomas Murray-Robertson
Board Member

LAST ISO Journal