Tag Archives: steinway

WGBH piano video shows mathematics in service of world culture

This video was created by WGBH Public Television Boston for the Annenberg Network series on Mathematics as an example of someone who has put Algebra to use in the real world in service of world culture.


There are three additions I’d like to make:


When using 1 gram blocks simulating the piano hammer out on the far end of a see saw,  the movie shows me placing the block on the table instead of on the end of the beam.

The reason, which is not shown,  is that I place weights along the beam to simulate all the parts of the key.  When they are in place then I place the 10gram weight on the end of the seesaw and slide it along until this beam is balanced.

How far out the weight is on the beams tells the weight ratio of the action.

Finding the position for a known weight on a see saw so that the see saw balances level is an analogy for solving an equation for a single unknown variable.


When displaying the hammer weight analysis of a Hamburg Steinway D in Jordan Hall, New England Conservatory of Music. The data shows a big dip in the weight.

This is the way it came from factory and it’s usually the hammer weights are found to be smoother in these pianos but you never know until you measure them..

What the video does not say is that the dashed lined on the graph just above the hammer weights is the new Precision Touch Design specification after  modifying and upgrading this action.

Lead weights were inserted into the wooden portion of the piano hammer to bring the weights up so specification.

The result is a more even and predictable result in the response of the keys and more evenness in the tone.   Bringing the weight level up also increases the projection of the sound and fullness of the tone which is important in a concert hall.


After showing a graph of how much lead weight is in the keystick from the factory and how the equation is used to smooth out the weight inconsistencies, I mention that we use a wippen support spring added to the existing parts.

A combination of spring tension and lead weight is used to create a faster, quicker action without giving up hammer weight and tone.

It should be noted that we do not do this to all Stanwood Action jobs.  It is what we call a “High Performance Option”.

piano restoration: invention certainly accounts for our busy shop and backlog

cllahan piano serviceLetter from John Callahan

We are Callahan Piano – one of the few “Left Coast” Stanwood connections.

It was great to have a small group of installers gather recently after the CA State PTG convention. All Stanwood folks have an open invitation to come and visit whenever you find yourselves in the Bay Area.

We are a fair sized shop specializing in high-end piano restoration – 95% Steinway and Mason & Hamlin.

We are pleased and proud to have four licensed installers working together under one roof – and complete an average of two PTD’s per month. We are a bit different in that we restore for clients only – we do not buy and sell.

Licensed Installers since 2001, we made the decision some time ago not to do an action job without PTD – and that certainly accounts for our busy shop and backlog.

The more Stanwood actions we do – the more folks want it.

When a potential client can visit the shop and play one, and sometimes two or three pianos, all with the same mind-blowing ease and evenness – the decision to have us do their action becomes easy.

Our success over the past few years has been the result of fairly intense marketing efforts to get local pianists and potential clients into the shop whenever we have a completed instrument.

We have also found it very effective to host “send-off” parties on completion of a major restoration. The client invites friends and colleagues, and we supply wine and cheese, and the piano is the star of the evening. Lot’s of fun. (And the biggest plus – it gets the shop cleaned up!).

Thanks to David for all his work which has benefited so many technicians and pianists!

Best regards to all,


John Callahan, Callahan Piano Service

steinway m: transformed; sound is incredibly beautiful,voicing perfect


Letter written to John Callahan, PTD installer in Oakland CA

Dear John,

It was with some fear and trepidation that I submitted my 1962 Steinway Model M to you for a complete action restoration last September.

Just one year earlier, my piano technician had replaced the original hammers with new Steinway hammers, with disastrous results. After his repeated efforts, adding lacquer, then punching, then more lacquer, over and over again, I finally gave up.

After all his work, the action felt like that of a truck and the sound was harsh. Needless to say, I didn’t enjoy playing the M after that.

Fortunately, I subsequently heard of the Stanwood action balancing system and that your firm used the system. Based on several glowing recommendations, I decided to have you do a complete action restoration, including new Ronsen hammers custom-made with European felt and new custom-made bass strings.

I can’t tell you how happy I am with the result. The action is totally even, responsive and smooth as silk. The sound is incredibly beautiful, the voicing perfect.

Now I’m saving my pennies in anticipation of the day when I can have you design and install the Stanwood system on my relatively new (2000) Steinway Model B (I’m a member of the Palo Alto Two-Piano club).

It is a fine piano but has a fairly heavy action, nothing like the smooth, light action you gave my M. Because of the wonderful transformation you achieved on my M, I now find myself playing it almost exclusively (and it is the piano of choice with my two-piano colleagues). I’m afraid the B is feeling very neglected.

Thanks again for the fabulous work..

Carol Swenson
Stanford, California

pro piano: steinway d preferred by Krystian Zimerman refined and enhanced


June 26, 2001

“Onward and upward… the GREAT David Stanwood… did some GREAT work at/for/on Pro Piano”

– Ricard de La Rosa of Pro Piano

Background history:

Over the years Ricard de La Rosa has contracted with David Stanwood to refine and enhance the high quality of many new Hamburg Steinway Model D concert grands owned, leased, and sold by Pro Piano.

Ricard de La Rosa may be credited with nurturing this important path breaking research and work done by Stanwood, whose work is making important and historic improvements to pianos worldwide and raising the standard of piano making and piano playing world wide.

The most notable among these Pro Piano instruments improved by Stanwood was Steinway D Pro#0220 which was a favorite of Krystian Zimerman, the famous Polish Classical Pianist.

Krystian Zimerman

“Zimerman toured with it for one full season. (D0220…) and it recorded several (he recorded on it, too… winning a Grammy and Disque  D’or, as well as the GRAMMOPHONE etc…. etc. the Ravel G Major with Boulez and Cleveland, etc.” – Ricard de La Rosa

keith jarrett : upgrades his steinway c says invention transformed his piano


“Your treatment transformed my piano… It opens the Microdynamic possibilities.”

Keith Jarrett, November 1997

Keith Jarrett, the world famous pianist, noted for his improvisations, recently had the Hamburg Steinway C c1978 in his home studio upgraded with a custom designed high performance Stanwood Precision Touch Design.

Chris Solliday, the Licensed Stanwood Touch installer from Deleware Water Gap, PA, worked with David C. Stanwood on the installation of Stanwood Touch and performed the fine voicing and regulating of Keith’s piano.