Why Aren’t Keyboards Divided Into an Even Number of Octaves?

Piano Lessons / music theory / Why Aren’t Keyboards Divided Into an Even Number of Octaves?

Welcome to LivingPianos.com, I’m Robert Estrin. Today I’ll be addressing a question from a viewer. Raymond asks, “On an 88 key piano, the lowest note is A and the highest is C. Why aren’t keyboards divided into an even number of octaves starting and ending on C or A?” This is actually a very good question because it seems so logical. In fact, if you ever look at five octave synthesizers and other portable keyboards, they almost always have an even number of octaves. From C to C, typically four or five octaves. So why aren’t pianos built that way?

Before the piano was invented, there were harpsichords.

Harpsichords had different numbers of keys and even different starting and ending points on the two keyboards, which is a whole story unto itself. The earliest pianos had a limited range of keys, typically around five octaves. You might wonder why. Well, it’s because those are the sounds those early instruments were capable of producing.

If you look at all the works of Mozart and Haydn, for example, they never really exceed that approximate range. It’s remarkable to think that all of the music they wrote was confined to this number of keys, because the piano just didn’t have more keys than that!

Beethoven worked closely with instrument builders expanding the range of the piano.

Expanding the range of the piano was no easy task! As you get higher, the tension of the strings becomes cumulatively enormous. So they started reinforcing the frame of the piano with metal, which eventually led to the full cast iron plate like we have today. Beethoven never reached the full 88 keys in his lifetime. But it’s interesting to see how the evolution of his music was affected by the capabilities of the instruments. Early Beethoven compositions had a much narrower range of keys than later Beethoven works.

How did the piano end up with 88 keys?

Late in the 19th century, most pianos ended at the highest A, and yet they went down to the lowest A. So there was a symmetrical keyboard in terms of the number of octaves! Eventually the high C became more and more common until it became the standard. So why doesn’t it go higher or lower? Well, to answer that question, there are a couple of instruments out there that do explore lower notes. The famous Bosendorfer Imperial Concert Grand, for example, goes all the way to C below the low A! It’s hard to discern pitch there, which is one of the reasons most pianos don’t venture below that low A. The lowest notes on the Bosendorfer Imperial Concert Grand sound a bit unearthly because the vibrations are so slow. You start hearing the separate vibrations instead of the pitch. Our brains almost don’t perceive it as pitch anymore! There is another instrument that also goes down to that low C and that is the Stuart and Sons from Australia.

Those instruments have those low notes, not just for those rare times when you want to take advantage of a lower octave. I know there are a couple of places in the literature where it would be really nice at least to have that low G or F. But it’s also because whenever you depress the sustain pedal all the dampers are released allowing those strings to sympathetically vibrate, giving more richness to the overtones of the sound.

What about the other end of the spectrum, going higher than the highest note of the piano?

Well, Stuart and Sons actually has a piano that goes higher than the high C. It goes all the way up to the high B, almost an octave above the highest C! Naturally the big hindrance with those really high notes, even the highest notes on any piano, is that they just don’t last that long. The notes die out in a matter of a second or two. Even the second to highest C on a piano doesn’t last very long. That’s why pianos don’t even have dampers for all those high notes. Dampers end on pianos somewhere in the D sharp to G range. Yamaha’s have dampers up to G. On Baldwins and Steinways, typically the last note that has a damper is D sharp. Do you need dampers on those high notes? Well, it does ring quite a bit. And you’ll find on different pianos, the dampers end in different places. But those extremely high notes have limited value because they don’t last long enough to use them melodically. They’re really just percussive little pecks of sound.

You can hear for yourself why they’ve settled in on A to C.

It’s a musically useful range of tones for the technology brought to bear. That’s the simple answer to your question, Raymond! Thanks for that very insightful question, I hope you’ve enjoyed this! Thanks so much for joining me, Robert Estrin here at LivingPianos.com, Your Online Piano Resource.

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5 thoughts on “Why Aren’t Keyboards Divided Into an Even Number of Octaves?”

  1. I wondered about this question, but never thought to ask anyone. I figured it was historical. Interestingly, when you play the lowest notes, I tend to perceive the first overtone, so I get pitch, but obviously I also hear the beat vibration or whatever you call it.

  2. I personally think best range would be F0 (F below bottom A) to F8 (F above top C). When I hear that bottom F0 I can tell it’s an F with no difficulty. Same with the top F8.

  3. Thank you Robert for an interesting answer and explanation why the piano cannot have more notes.

    It is important to think about the pedal as an extra dimension for creating overtones.

    I would like to know if the digital piano can produce an overtone?


    1. Any pitched sound contains overtones. This is not exclusive to musical instruments! So, yes, a digital piano produces overtones in the sound. Whether or not the pedal adds overtones as the sustain pedal on an acoustic piano does is determined by the programming of the instrument software.

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