Our Research   by   David Steinbuhler                                            

   From 1998 to 2005, Steinbuhler & Company extended an invitation to pianists to come to Titusville, Pennsylvania and discover what size piano keyboard most comfortably fit their hands. Looking back at the activity that took place in our “showroom”, I now realize that it constituted vital research.  To my knowledge, in the 300-year history of the piano, there has been no other comparable study.
   The hands we observed were ones that were not going to grow further; hands that had reached maturity both male and female. The pianists who came were motivated purely by the desire to find the keyboard size that best suited them. The environment we provided was one of relaxed comfort.  There were rooms where they could spend the night. In an uninterrupted afternoon or an entire weekend they would work with keyboards of every size.
   In addition to a Steinway B that was fitted with a complete range of keyboard sizes, we provided other pianos with conventional as well as smaller keyboards, which gave the pianists the freedom to experiment by going between pianos.  Also, as they desired, we would change the keyboard in the Steinway B to one that was slightly smaller or slightly larger. Always for me, the primary objective was to determine how many additional standards we should recommend and what sizes they should be.

Our Method
   For the purposes of this discussion, I will refer to the size of the keyboard by its overall width and assume it has 88 keys. The average modern conventional keyboard measures just over 48”.  The first keyboards we built were 42” in width. By 1998 we also had keyboards that measured 39” and 45”.
   With these three additional keyboard sizes to work with, we immediately learned that there was strong interest in more than just one additional standard. The great relief experienced by the 42” keyboard was accompanied by a desire to go smaller. There were also those pianists who desired relief from the pain and strain they experienced playing the conventional piano, but found the 42” keyboard too small.  It quickly became very clear we needed at least two more keyboard sizes in addition to the conventional keyboard.
   To determine the size of two additional standards, our next step was to do a thorough study at the small end of the range.  For this we built 5 keyboards that measured from 38” to 42” in one-inch increments. After establishing a practical small size we could then add the appropriate in-between size.

The Results
   When does the keyboard become too small?  One pianist told me she wanted to “walk 10ths like Oscar Peterson” and to do this had calculated she would need a 38” keyboard.  She flew all the way across the country to try our smallest keyboards to discover they became too cramped for her.
   There was always the secondary consideration of the width of the sharps and the tradeoff that exists between the landing area on the sharp’s top and the space between them. After some experimentation, we found it prudent to keep close to the natural/sharp ratio found on conventional keyboards.
   Measuring dozens of hands, comparing them to the full range of hand sizes found in mature pianists, listening to the feedback, and seeing what size keyboards were purchased, soon lead us to an appropriate small size.  For pianists whose hand spans are in the 7” to 8” range there was a desire to go smaller than the 42” keyboard as everyone wants to play 10ths comfortably. But once they went below a 40” keyboard the space between the sharps was becoming too confined for all but the smallest hands with thin fingers. It became clear the 41” keyboard was the best overall choice even though 10ths were still out of reach for the smallest hands.
   Defining an octave as the distance from the left side of one C key to the left side of the next C key, the size of the octave of the modern conventional keyboard is 6.5” (see below).  We then used the DS Standard™ Keyboard Ratio which is 48/52 or 12/13 to calculate the smaller keyboard sizes.  In addition to the two smaller keyboards for adult pianists, we also added a third smaller size for small children and established the following standards (see DS Standard™ Keyboard Ratio):

Conventional Keyboard -   6.5”   or   165.1mm   octave 48.25” overall width  - Large 15/16 - DS Standard™ Keyboard -   6”       or   152.4mm   octave 44.54” overall width  - Universal 7/8 - DS Standard™ Keyboard -   5.54” or   140.7mm   octave 41.11” overall width  - Small 3/4 - DS Standard™ Keyboard -   5.11” or   129.9mm   octave 37.95” overall width  - Child

Discussion
   It was interesting to observe that small changes in keyboard size did not make much difference to pianists once they had gotten to a size that was “in their zone.”  For instance, we built a 46.37” keyboard and a male with an average hand would notice little difference, whereas a small handed pianist would immediately notice relief.  The exact sizes for the standards were not that critical.
   Although we suggested a keyboard that was larger than the conventional keyboard, no pianist requested to try it.  Given the fact that the large conventional size already exists, we feel confident we are offering nearly optimum sizes for every adult pianist.   For small children we have added another keyboard the next size down.
   Focusing on adults, all of our observations relating hand span to keyboard size are summed up in the chart below. Notice the keyboards are divided into three overlapping zones allowing for differences in finger thickness and personal preference.   Although some pianists have purchased custom keyboards, there is no compelling need to have more than these three recommended standards.   As can be imagined, the greatest need in leveling the playing field is for the 7/8 - DS Standard™ Keyboard.

The hand span data in this chart was collected at the 2004 MTNA National Convention.

There is a beauty to the sizes and nomenclature we have chosen.

• The octave has been defined and a very accurate method to measure it on a piano has been provided.
  (see Measuring an Octave)  Measuring today’s pianos we find their octaves vary in a small range from 6.46
  to 6.54 inches and that most manufacturers have gravitated to an octave size that is very close to an even 6.5 inches.  So we establish the conventional keyboard octave at 6.5 inches.
   
• The jumps between our keyboard sizes are comfortable, all having the same percentage of change.
  (see DS Standard™ Keyboard Ratio)  The 15/16 - DS Standard™ Keyboard has an octave of exactly
  6 inches and being the middle size is thought of as “Universal”.
   
• A pianist can feel the size of the octave on a  7/8 - DS Standard™ Keyboard  by playing a seventh on a conventional keyboard.
   
• Consider the nomenclature 15/16, 7/8, and 3/4.   While the nomenclature does not have our ratio between the sizes, they are approximately the actual sizes.  And notice the pattern; 15/16 is one less then 16/16; 7/8 is one less than 8/8; and 3/4 is one less than 4/4.  Also, going from fourths to eights, 3/4 becomes 6/8 and adding one produces 7/8.   Likewise, going from eights to sixteenths, 7/8 becomes 14/16 and adding one produces 15/16.  All this is aesthetically pleasing. 

Today, the world of the piano has a one-size-fits-all mentality producing profound discrimination and severe medical issues.   If you ask pianists what size keyboard they need, they are confused and do not know, having spent their life in this one-size-fits-all world. Because of our experience watching how pianists respond to a complete range of keyboard sizes we can offer this elegant set of standards.   It is similar to the idea of offering various sizes in the world of the violin without the disadvantage of having to play a smaller instrument.    The smaller keyboards fit into all the modern powerful pianos.    Regardless of a pianist’s hand size, the Power, Ease, and Artistry, available in the modern piano, is now within her Reach.

Keyboard Size History
   Naotaka Sakai measured 75 historical pianofortes found in the collections of the Metropolitan Museum of Art in New York, the Hofburg Collection of Early Musical Instruments in Vienna, the Technisches Museum Wien in Vienna, and the Hamamatsu Museum of Musical Instruments in Hamamatsu, Japan. He published his findings in the Medical Problems of Performing Artists[1]. Converting his data to conform to the Steinbuhler definition of an octave (see Measuring an Octave) and assuming a keyboard of 88 keys to calculate its overall width we have the following history for piano keyboard size.

• A 1720 Cristofori keyboard was the same size as today’s conventional keyboards:
  

  6.5” or   165mm   octave 48.25” overall width

  
   
• From 1784 - 1825 keyboards were somewhat smaller ranging in size from:
  

  Smallest -   6.13” or   156mm   octave 45.5”  overall width Average -   6.3” or   160mm   octave 46.8”  overall width Largest -   6.4” or   163mm   octave 47.5”  overall width

  
  
  
  
   
• From 1826 - 1875 keyboards were getting larger and ended in today’s conventional size.
   
• From 1876 - 2000 keyboards were the same as today’s conventional keyboards:
  

  Smallest -   6.46” or   164mm   octave 48”      overall width Average -   6.5” or   165mm   octave 48.25”   overall width Largest -   6.54” or   166mm   octave 48.5”    overall width

  
  
  
  
  
  
• A notable exception; in the 1920’s & 1930’s Joseph Hoffman performed on a 7/8 keyboard built by Steinway:
  

  5.66” or   144mm   octave 42”      overall width

  
   
• Steinbuhler & Company keyboard standards:
  

  Child -   5.11” or   129.9mm   octave 37.95”   overall width - 3/4 - DS Standard™ Keyboard Small -   5.54” or   140.7mm   octave 41.11”   overall width - 7/8 - DS Standard™ Keyboard Universal -   6” or   152.4mm   octave 44.54”   overall width - 15/16 - DS Standard™ Keyboard Large -   6.5” or   165.1mm   octave 48.25”   overall width - Conventional Keyboard

  
  
  
  

   Note that Mozart, Beethoven, Schubert, Chopin, Schumann, would have composed many of their great works on keyboards that were smaller than our present day conventional size. This makes it doubly understandable why pianists today with small hands will struggle to perform them.
   One reason conventional keyboards are so large was do to the fierce pressure in the 19th century for piano manufacturers to win competitions.  They were driven to produce pianos that had ever bigger sound which meant they would build pianos with more strings and ever bigger hammers. Cristofori’s first keyboards were the same size as in today’s modern pianos, but the initial reaction to his keyboard was to build smaller ones.  Then in the 19th century as manufacturers strove for market share, designs for the modern piano evolved and pushed the width of the keyboard back out again.  However, today it is possible to have pianos with very big sound and also to fit them with keyboards that are ergonomically suited to every hand.

Notes
1. Naotaka Sakai, MD, PhD: Keyboard Span in Old Musical Instruments, Medical Problems of Performing Artists, December 2008

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