Are Mini-Keys a Deal Breaker?

What history tells us about that mythical standard-size keyboard
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How many times have you heard someone say “I’d buy the ______ synthesizer, if only it had normal keys…”

What instrument would you pick to fill in the blank? The Korg minilogue, Yamaha Reface, or ARP Odyssey re-issue? The list goes on and on. I’ve heard this comment more times than I can count, but it got me thinking, “What is a normal key?”

I’m not daft. I get it. The comment is made in reference to an 88-note, full-size piano keyboard. (Oddly, no one has ever approached me and exclaimed, “If only this instrument did nothing else but took up 30 to 50 percent more space in my studio.”) Still, the question remains: “Is there a standard for key shape and size?

In short, the answer is both yes and no. It’s a moving target and has been for centuries. Keys have come in all manner of shapes, sizes, colors, and textures. Throughout history, from brand to brand, and even from model to model, the dimensions of the keys can change wildly.

Moog Minimoog

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For example, the white keys on a modern piano are roughly 152 mm (6") in length, although the key mechanism may extend much farther inside the instrument. And despite historical and other influences, the natural keys on a modern piano are about 23.5 mm wide at the front edge, while accidentals run about 13.7 mm in width, creating an octave span of some 165 mm.

Minute changes in the size of individual keys may be hard to notice to the unaided eye. But adding even a single millimeter to each key can have a profound effect. Historically, the octave span for the piano has ranged from 125 to more than 180 mm. Over time, the octave span for a modern piano has settled in at about 164 to 165 mm. The width of the natural white keys at the front edge remains constant from key to key. The accidentals also have a consistent width, but the width of the thin shank of the white notes between the accidentals will vary, allowing the octave span to remain nearly constant in any key.

But not every player has the same sized hands, and the current octave span of the modern piano carries the legacy of male euro-centric design. Taken as a whole, women are some 15% smaller than their male counterparts. Women may have proportionally longer fingers, but their overall hand size remains smaller, and European men tend to have larger hands than their American and Asian cousins.

Steinway worked with inventor and small-handed pianist Josef Hofmann to create their now standard Accelerated Action, and it is said the company made a special piano with smaller keys for his use. Christopher Donison and David Steinbuhler are advocates of their DS5.5 and DS6.0 Ergonomically Scaled Piano Keyboards that are reduced to a ⅞ and 15/16 size, respectively, from the existing norms.

Korg MicroKorg

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Electronic instruments can also be vexing. Whereas the Yamaha MOTIF FX6 and FX7 have an octave span of 159 mm, the MOTIF XF8 runs 164 mm. This may seem rather arbitrary at first, but there are unseen forces churning away behind the scenes that have influenced and continue to steer the design and implementation of such widely varied keyboard schemes.

In addition to introducing the Hammond organ back around 1935, Laurens Hammons also introduced the plastic Waterfall keyboard. These so-called waterfalls keys did not have the same protruding lip as piano keys. Instead, the top and front edges of the key were joined by a continuous curve. While Hammond is said to have created this key as a money-saving measure, the design welcomed the sliding smears and glissandi favored by Hammond organ performers. And even though there was still no standard piano key-size, the Hammond organ keys were distinctively piano-ish.

That all changed in 1940 with the Hammond Solovox. One of the first commercial monophonic synthesizers, the Solovox was designed to mount under the keyboard of a traditional piano. Its keyboard had to be shallow in depth, as it needed to be played and positioned between the performer and the front edge of the piano.

Korg Volca FM

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But in order to be compatible with piano fingering, the keys needed to share the same width as the piano keys—that is, the notes of the piano needed to line up with the notes of the Solovox. The result was a unique stubby key format. The synthesizer age was upon us and, moving forward, damn near anything could be a key.

Since their earliest days, synthesizer keys have taken on all types of shapes and proportions. The Minimoog had white keys projecting out with no front face and a hollow area underneath. Other early synths, like the Roland SH-3, had a blunt front to each key, with no overhang, that presented a stocky, solid appearance.

Depending on the design of the instrument, the accidentals were either a consistent height from front to back, or tapered down in the back to where the key met the panel. Yet despite all the variations, certain similarities began to occur. Why, you may ask?

Yamaha Reface YC

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After the ivory trade dried up, Pratt & Read, who specialized in ivory key-tops for pianos since the 19th century, began making electronic and plastic keybed assemblies. By the 1960s and ’70s, they were making keybeds for many of the popular stateside synthesizer companies of the day: ARP, Aries, Electrocomp (EML), Moog, Oberheim, Sequential Circuits, and so on.

Why? For the manufacturer, it was more efficient to buy the keyboard assembly from a specialized manufacturer. The same holds true today.

Years ago, the Adriatic coast of Italy was ground zero for accordion manufacturing. As the electric organ usurped the accordion’s role, the Italian government offered incentives to some of these manufacturers to help them transition to electronic instruments. Farfisa, Elka, Siel, and other companies made Italy a hub for electronic keyboard manufacturing. Fatar also sprang up in Italy and today provides keybed assemblies to many companies across the globe.

Some manufacturers still produce their own keyboard mechanisms—but not all, and not all of the time. During the heyday of the workstation, Korg purchased certain keybeds from Yamaha. This is one of the reasons that both Korg and Yamaha offered a 76-key version in the past, while Korg now offers their workstations with a 73-key non-Yamaha action.

As synthesizers, digital pianos and other electronic keyboards evolved, so did the keys. New surfaces were designed to imitate the feel of ivory and ebony more accurately. Proportions vacillated between short and stubby to long and lean. Our so-called full-size synthesizer and electronic organ keys hovered between 127 and 143 mm in length; digital pianos are longer, roughly in the 152mm range (the same as a current Yamaha grand piano).

There have always been exceptions. The Kawai K-5000 additive synthesizer, for example, had 152mm keys, more in scale with a piano. In addition, the accidentals were somewhat textured and each key was slightly crowned to make playing more comfortable.

Arturia MiniBrute SE

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And that brings us back to the nonstandard sizes that started this conversation. The flat key is both a relic from the past and a force for the future. Synthesizers from Buchla, Serge Modular Systems, and Electro-Harmonix used a series of flat keys. Today, the Korg volca series continues to use flat keys, whereas the Haken Continuum, Roli Seaboard, and the smart-fabric Keith McMillen K-Boards provide unbelievable expression from a pliable flat surface. Taken a step further, the Moog Music Animoog and Moog Model 15 apps for iPad deliver a very expressive performance by interacting with the on-screen keys using position and Multi-Touch gestures.

But if you go back to the Roland TB-303 Bass Line, MC-202 Micro Composer or Casio VL-1, you’ll find keys that were nothing more than buttons laid out in the five-over-seven keyboard pattern. The TB-303 and MC-202 were inherently production pieces, with no aspirations to be performance instruments. As such, the small-scale buttons were a space-saving advantage.

And even micro and mini keys are nothing new. The Yamaha Portasound and Casio SA models elevated the mini-key keyboard above the “toy” status back in the ’80s. On the stand-alone synthesizer side, look no further than the Casio CZ-101, Yamaha DX-100, and Korg microKORG, just to name a few. Despite some initial resistance to its smaller keys, the microKORG is still on the market a dozen years on.

Yamaha MOTIF XF6

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This article began with a wish for full-size keys, and for the proficient keyboardist, that wish is understandable. Consequently, a MIDI connection to a hammer-action keyboard controller may be the answer.

On the other hand, many artists simply want something small enough for the desktop, in any combination of lightweight, portable, and inexpensive. For those who consider the keyboard as simply another button to trigger events, key size and shape are, at best, secondary considerations.

Visit to read the author’s deeper examination of the historical development of the keyboard.