The DS Standard Registry
Certified keyboard sizes that belong to pianists, not to the companies that build the instruments.
For more than three centuries the piano keyboard has been manufactured in essentially one size. A single width, fixed in the late nineteenth century, has asked every human hand to bend itself to the same geometry. The DS Standard is the first formal registry of alternatively sized keyboards: a small family of certified specifications, each engineered to meet a different hand where it actually lives.
The aim is not to replace the conventional keyboard, but to place it in honest company. Pain should not be a prerequisite for musicianship, and a student’s span should not quietly decide which repertoire they are allowed to love.
The width inherited from the late nineteenth century. It rewards a long reach and quietly disadvantages the majority of adult female pianists along with a sizeable cohort of male hands.
The middle specification of the registry, and the one most often chosen by institutions. Nearly every adult hand finds relaxation here without losing the geometry of the traditional keyboard.
The seven-eighths keyboard, engineered for smaller adult hands. It offers the pianist of average span the freedom historically enjoyed only by very large hands.
Late primary pedagogy, where repertoire complexity begins to outpace physical growth.
The 3/4 keyboard. A widely adopted intermediate size for developing hands.
Early polyphonic work, kept within easy reach so no chronic tension accrues.
The 5/8 keyboard. A comfortable entry point for the youngest pianists.
From 1998 to 2005, Steinbuhler & Company (which would become the DS Standard Foundation in 2018) invited pianists to Titusville, Pennsylvania, to find out, at their own pace, which keyboard size actually suited them. The welcome was simple: coffee, several pianos, keyboards of different widths on the bench, and an afternoon or a weekend to play them.
What looked like hospitality at the time, we now understand was research. As far as we can tell, nothing comparable has happened in the 320 year history of the instrument. The hands we observed belonged to mature adult pianists, both men and women, every one of them motivated simply by the hope of finding a keyboard that felt right.
The environment we provided was one of relaxed comfort. There were rooms where pianists could spend the night, so that in an uninterrupted afternoon, or across an entire weekend, they could work with keyboards of every size. A Steinway B was fitted with the complete range of keyboard sizes; alongside it, other pianos stood ready with conventional as well as smaller keyboards, giving pianists the freedom to experiment by moving from one instrument to another. When they wished, we would change the keyboard in the Steinway B to one slightly smaller or slightly larger, so the comparison could continue at the same piano.
The patterns in that room eventually became the registry you see on this page. The dimensions are not guesses; they are what real pianists, working without anyone looking over their shoulder, kept reaching for.
Our primary objective was to determine how many additional standards we should recommend and what sizes they should be.
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", so that we could watch pianists slide between them.
With these three additional sizes to work with, we learned very quickly that there was strong interest in more than one additional size. The great relief pianists felt on the 42" keyboard was almost always accompanied by a desire to go smaller still. Others welcomed the relief but found 42" too small for their own hand. No single reduction solved the problem.
It became clear that we needed at least two more keyboard sizes in addition to the conventional keyboard to satisfy the range of adult hands. That realisation is what turned a set of prototypes into a standard.
To determine the exact sizes, the next step was a thorough study at the small end of the range. For this, we built five keyboards, measuring 38, 39, 40, 41 and 42 inches. Once a practical small size was established, we could then add an appropriate in-between size.
Five keyboards, the small-end study
One pianist told me she wanted to “walk 10ths like Oscar Peterson,” and had calculated that she would need a 38" keyboard to do it. She flew across the country to try our smallest keyboards, only to discover that they were too cramped for her own hand.
There was always a secondary consideration: the width of the sharps, and the tradeoff between the landing area on the sharp’s top and the space between them. After a great deal of experimentation, we found it prudent to stay close to the natural-to-sharp ratio found on conventional keyboards.
Measuring dozens of hands, comparing them against the full range of hand sizes found in mature pianists, listening to feedback, and watching which sizes were actually purchased: all of it pointed to one conclusion. For pianists whose hand spans were in the 7" to 8" range, there was a real desire to go below 42" (everyone wants to play 10ths comfortably). But once we dropped below a 40" keyboard, the space between the sharps became too confined for all but the smallest hands with the thinnest fingers. The 41" keyboard turned out to be the best overall choice, even though 10ths remained out of reach for the very smallest hands.
The conventional octave, specified
6.50" octave, with a tolerance of ±.04".
Every piano keyboard in use today hovers around a 6.5 inch octave, and the octave size of all conventional pianos stays within a .04 inch range of that number. We therefore set the standard for the conventional keyboard octave at 6.50 inches, with a tolerance of ±.04 inches.
To find the appropriate middle keyboard, it was clear the ratio between the conventional keyboard and the middle size needed to match the ratio between the middle size and the keyboard at the small end of the range. The ratio 48/52 gave us very attractive properties. Most importantly, it produced a keyboard whose overall width was slightly larger than 41 inches, which is why it became the governing ratio between every certified size in the registry.
In addition to the three keyboards for adult pianists, we have recently added smaller sizes for children. Experimenting with those, we are now building a DS4.0 keyboard for the Steinway B; initial tests are showing that it will be possible.
Every step of the registry is governed by a single ratio (approximately 0.923). Multiply any certified octave by it and you land, cleanly, on the next smaller size.
It is an elegant piece of arithmetic, and a practical one: the same hand-to-keyboard relationship repeats consistently from the conventional keyboard all the way down to the smallest child size.
How the octave is measured
A very accurate octave measurement is obtained by taking the distance from the left side of the piano’s first C key to the left side of the eighth C key, then dividing that number by 7.
Should a larger keyboard ever be needed
The ratio provides an elegant fit: reduce the number of natural keys from 52 to 48, losing three notes at each end of the piano, and the next larger size fills the available space without altering the instrument.
Roughly three centuries in which the piano keyboard has been built to essentially one dimension, no matter who was sitting in front of it.
Three specifications for adult hands and four for young pianists, each dimensioned by research and each built to the same geometric law.
One ratio (approximately 0.923) connects every certified size in the registry, from the conventional 6.5 inch keyboard down to the smallest 4.0 inch child size.
It was interesting to observe that small changes in keyboard size did not make much difference to pianists once they had reached a size that was “in their zone.” When we built a keyboard with a 6.24 inch octave, a male pianist with an average hand noticed little difference, while a small-handed pianist noticed immediate relief. The exact sizes for the standards turned out not to be that critical.
Starting with Dr. Carol Leone’s research at Southern Methodist University in the year 2000, ongoing university studies have never demonstrated a need for other sizes. Rhonda Boyle in Melbourne has compiled and analysed a great deal of data on hands and piano playing that agrees with our findings, the main point being a roughly 1 inch average difference between male and female hands.
Although we offered a keyboard larger than the conventional size, no pianist ever asked to try it. Given that the large conventional size already exists, we feel confident that the registry offers nearly optimum sizes for every adult pianist. The keyboards are best understood as overlapping zones that allow for differences in finger thickness and personal preference.
DS6.5®
Conventional
DS6.0®
Universal
DS5.5®
7/8 Keyboard
Any piano certified by the DS logo, whether as a result of its original manufacturing, retrofitting, or a rebuild, is guaranteed to conform to one of the corresponding DS Standard sizes within a tolerance of ±.04 inches.
A chance meeting in the summer of 1991 changed my life. I was visiting the Shaw Festival in Niagara-on-the-Lake and, as luck would have it, stayed at the bed and breakfast run by Christopher Donison, the festival’s music director.
Christopher had a 7/8 keyboard fitted into his concert grand. An octave on his keyboard was equal to a seventh on a conventional one. He explained, almost matter of factly, that while he was studying music at the University of Victoria he had realised that his small hand was quietly closing off much of the great piano repertoire to him.
I play the piano a little. What startled me was how naturally I adapted to his smaller keyboard, and how clearly Christopher described the new world that had opened up to him the first time he sat down at one.
“This,” I said, “is a big idea.”
David Steinbuhler, Founder
With no preconceived ideas about how keyboards ought to be built, I began tinkering more or less as a hobby. One thing led to another, and in the summer of 1994, on the loading dock of our textile plant, using a computer driven router, a coworker and I finished our first keyboard.
Linda Gould, an acquaintance of Christopher’s, flew from Victoria, British Columbia, to try it. Years earlier she had set aside her dream of becoming a concert artist because of the pain she felt every time she played.
I will never forget her exclaiming “It IS Easy!” after spending one emotional afternoon at the instrument.
Linda decided on the spot to order a keyboard for her Yamaha grand. Two months later we sold our first DS Standard keyboard.
Our Music and Medicine department has conducted ground breaking research on the relationship of hand pain in small-handed pianists to the use of the standard size keyboard. And simultaneously, hard evidence that for smaller hands, the smaller piano keyboard dramatically REDUCES this pain.
It is incomprehensible to me that the major piano manufacturers have not seen the economic advantage to them of producing these smaller keyboards.
We pianists and teachers can certainly see the pedagogical advantages of training a young musician on an instrument that fits their body.
David supplies a kit of jigs and measuring tools that make it possible for a competent piano technician to take the precise measurements a DS keyboard requires. He has built many DS keyboards for American universities, and the first international order travelled to Australia, for the musician Rhonda Boyle.
Building keyboards across borders quickly raised a practical question: how does one measure a piano one cannot visit? Within the United States, David can drive out and measure the instrument himself. For overseas orders this is rarely feasible. The technician’s kit exists to close that distance, by equipping trusted technicians with everything they need to send accurate measurements back to the workshop.
Review certified keyboards and components, or write to the Foundation about institutional acquisition, credentialing, or a pianist’s individual search for the right size.