If Size Matters, How Do We Measure It?

5 November 2018

By Project Founder, Prof. David Francis Urrows

In the course of China’s ‘organ race’ (see FAQs) the issue of the size of organs has been a prominent theme. The Project has recorded comments about this one-upmanship feature of the race, and the sometimes odd or purely symbolic decisions to build (or at least label) organs with specific numbers of stops, such as the 88 stops of SHA2005, and the 56 stops of ORD2010.

The problem with defining the size of a pipe organ is a fraught business, and only gets more complicated as the size of the instrument increases. There are three basic measurements:

  • Number of stops
  • Number of pipes
  • Weight

All three of these are not as clear as they might appear at first, and are subject to manipulation. Does the number of stops include only the number of real stops, or of all speaking stops? That is, are we counting the stops backed up by an actual rank of pipes, or ranks extended, transmitted, borrowed, or otherwise re-utilized by the builder to create a new stop out of an existing stop?

The number of pipes is even more open to deceptive practices, since certain types of stops use multiple pipes per note (as with Mixtures and Mutations.) Thus an organ builder can bulk up the pipe count, at little expense, by including many mixtures and mutations in the instrument without making it bigger in a tonal, or musically significant way.

Weight is the crudest measure of size, and only really an issue with very large organs.

Recently, an attempt to establish a metric which rationalizes all these issues was published in the online journal of the American Guild of Organists (AGO), Vox Humana. This system, devised by Polish organist Michał Szostak, uses a form of real rank count to gauge the size of a very large organ. This system privileges organs with lots of mixtures: but it also makes allowance for stops that are not full-length, and averages out mixtures with varying numbers of pipes per note. The article can be found at:  


The greatest battle of the largest organs has always been between the Atlantic City (NJ) Boardwalk Hall Organ, and the Wanamaker Organ in Philadelphia. Using Szostak’s system, Atlantic City comes out ahead due to its rank count (517 vs. 470), even though Wanamaker has more stops (395 vs. 381). He provides charts for the largest organs in the United States, Europe, and the world. It is significant that the majority of the instruments in these charts are located in either the U.S., or Germany.

How this metric would apply to the question of the size of some of China’s larger organs, such as HKG1989, CAN1995b, PEK2007a, and FCW2017, is not entirely clear. It would be extremely interesting to follow up this exercise, but it is difficult to get accurate specs for some of these instruments, as has been noted in Keys to the Kingdom and elsewhere on this website. However, it also remains to be seen what criticism Szostak’s system will encounter, and how widely it may be accepted and used in the future.