Why is the lowest note on the piano an A?

Question

I've always wondered why almost every piano's lowest note is an A. In fact, I've never seen a piano whose lowest note is not an A, and I have also noticed that this pattern only occurs in pianos; most keyboards I've seen have a C or a G as lowest note.

This question's top voted answer touches this subject, but doesn't give a reason as to why the lowest key on almost any piano is an A.

Possible answers I could think of is that it's because of certain history, harmonics, convenience, compatibility with other instruments, or sheer coincidence.

Answer 1

Early pianos started out with the existing range of harpsichords, having between four and five octaves, usually starting at low C. This stands to reason, because Bartolomeo Cristofori, generally credited with being the inventor of the piano, was an expert harpsichord maker. By the time of Mozart, the range had standardized to five octaves, starting with the F below low C, a sixth above the bottom A on modern pianos.

Beethoven's favorite piano was the Broadwood "fortepiano", of which many replicas exist and on which performances of Beethoven's music are often heard. For reference, I will mention that, in school after hearing a performance of some of Beethoven's sonatas on such a replica, four piano students and the pianist took the legs off of it and lifted it into the back of the pianist's van. Not the same instrument as we have today!

Now, Beethoven wasn't always happy with the limitations of the keyboard range. There are all sorts of famous examples in his sonatas of his working around these limitations, leading to scholarly arguments on whether it's ok to add in some of the notes that he left out in performance. (Here's an interesting article on the subject.) The pianos kept adding keys during Beethoven's life, extending from five to seven octaves by 1820 or so, and some of his later work incorporates some of the new notes. So, it can be argued that Beethoven provided at least some of the impetus to expand the range beyond that current in his lifetime.

Eventually the range stabilized at what we have in the present. Part of the reason we don't have higher notes is that the strings would have to be too short to accommodate the requirements of the action. Also, at the higher end of our audible spectrum, it's difficult to distinguish between pitches, so perhaps part of the reason is that further extension probably wouldn't yield much musical value anyway.

On the low end, the impetus to expand the range slowed down as we began to get to the low end of the audible spectrum. The low end of the audible spectrum is generally said to be somewhere between 15 and 20 Hz. Now, the lowest A on the modern piano is about 27.5 Hz, which is getting close to the edge of our ability to hear. Adding nine notes on the biggest Bösendorfer gets the lowest note down to 16.5 Hz, which can be barely heard if at all by most people.

In the very low notes, most (if not all) of what can be heard is actually the overtones of the note. That's why they sound a bit "muddy". The existence of lower notes than are generally used adds to the resonance of higher notes, so that's also one of the reasons that we have them.

To demonstrate this, here are two examples from piano literature that actually use the lowest A. The first one is Debussy's Isle Joyeuse, and the note occurs on the last note of the piece. Skip to the end, and if you listen to it, you'll notice that the note itself is a bit unclear. You know what note it is partly from the context of the rolled chord--the chord tells you where it's going, if you will.

The next one is Brahms' Rhapsody Op. 79 No. 2. Look at the last quarter note in the second measure, and even more strikingly on the next page, second line, last measure where the fermata is. You'll notice that the doubling of the A with the next octave up gives it more of an "A feeling" than you have in the Debussy piece.

So, to sum up my answer: pianos have evolved to the point where the pitch range is pushing the envelope of useful pitches, given the limits of audible range, how we hear pitch, and the nature of the piano tone. The two largest Bösendorfer models notwithstanding, adding more keys to the piano doesn't add much in the way of usable musical materials.

Answer 2

You must not have heard of the Bösendorfer Imperial 290 piano, which has 9 extra notes lower than "A", for a total of 97 keys. The soundboard is 2.9 meters in length. It is a popular model in large churches and concert halls, but it is very expensive at around €150.000. It has been on the market for more than 100 years. The Bösendorfer company is in Vienna, Austria.

For 100 years, Bösendorfer has owned the market for anybody who has a special need for a piano that goes below the conventional low "A".

The existence of the Bösendorfer 290 and its 100 years of success proves that there is no technical reason that the conventional low "A" is some kind of limitation that cannot be overcome. However, to the best of my knowledge, no other piano company has ever mass-produced another model of piano with notes lower than the conventional low "A".

The obvious reasons why all other piano manufacturers stop with the low "A" are that economic factors would make it impractical for them to copy what Bösendorfer has succeeded in doing. It seems to be that developing the tooling to manufacture such a huge piano would be too expensive, that the pianos would have to cost a great deal of money, and that there would be a limited number of people willing to buy them.

Furthermore, as the standard low "A" has been established for about 150 years, there are virtually no compositions that call for a note lower than the low "A". I suspect that composers have not written any music that calls for lower notes because those composers either did not have access to a Bösendorfer 290, or that they realized that it was unlikely that other musicians wishing to buy the sheet music and perform those compositions would have access to a Bösendorfer 290 upon which to play them.

Answer 3

The fact that a piano can go down to low "A" depended entirely upon the railroad and shipbuilding industries of the 1800s. It had little to do with the wishful thinking of artistic considerations. Read on and I will explain.

I had so many comments to make that I decided I needed to add another answer. @RockinCowboy cited one lone source that implied that the expansion of the range of the notes on the piano was in response to the desires of composers for artistic reasons. I don't agree. Google history of piano and you will find many sources that paint an entirely different picture. You will find many timelines listing technological innovations by builders. You won't see much of anything said about what the composers wanted or requested.

This can be clearly seen: For centuries harpsichords were made of only a wooden frame, and the only available material for strings was plain brass wire. The range of notes stayed the same, at 4-1/2 to 5 octaves. Even the invention of the piano could not go beyond that. The earliest pianofortes in the 1720s had a plain wooden frame strung with plain brass wire, and the same 5-octave range as the harpischord. They stayed that way for almost another century.

I'm sure that composers in Bach's time wanted more notes on a keyboard, but it was practically speaking impossible to build a larger keyboard with more notes.

Harpsichords with a full 5 octaves had very long frames to accommodate the plain thin brass strings that had to be very long to play those low notes. The next innovation was to create wound bass strings -- a plain brass core around which another brass wire was wrapped. That helped a bit, but the wound brass strings were still too brittle for higher notes -- they would break. They still had poor vibrational properties for those lowest notes. Then there was the matter that a purely wood frame could not handle the additional string tension. At this time nobody knew how to build anything that would perform better.

No, the expansion to more than 5 octaves had to wait for the technological innovations in forging, casting, and drawing iron and steel on an industrial scale. These began to happen around 1810. The Industrial Age dawned. Vast foundaries and factories were developed to smelt iron and steel and cast it, and to build railroads and iron-clad battleships.

It was only from this point that the expansion of the number of notes on the piano was finally able to happen -- and it happened rapidly. It was as if a dam burst.

One innovation that came about this time was the invention and use of iron strings, but they were only tried for a short time, because iron strings corrode rapidly and don't produce a good tone. Later a tremendous breakthrough happened: the invention of carbon steel strings and wound steel strings. This enabled rapid innovation.

Read about the History of Piano Wire at Wikipedia. This will explain a great deal.

Around the same time, new technology for making cast iron bars came into play. Builders incorporated cast iron bar reinforcements into the wooden piano frame. In tandem with wound steel piano wire strings, it was now finally possible to build larger pianos with extra low and high notes.

The next huge leap forward was the invention of the solid cast-iron piano frame (sometimes called the plate or harp), which happened from the late 1820s (Chickering) into the early 1850s (Steinway). This enabled the piano design quickly to expand to its current 88 notes.

I found a great lecture online explaining the physical limitations faced by the first piano, Cristofori's invention of 1720, and how the cast-iron piano frame and steel piano wire strings had to be invented first to overcome these problems.

http://www.speech.kth.se/music/5_lectures/conklin/thecastiron.html

The ability to build a piano with 88 notes followed after the development of factories that built out railroads that criss-crossed the world, and shipyards that built iron-clad battleships. If you don't believe this, the only other possible explanation would be that the railroad and the shipbuilding industries were dependent upon and got their technology from piano manufacturers. This is obviously not the case.

There were many other technological details of the piano that had to be invented and refined and manufactured as well. These had to do with the action and mechanism of the hammers and the keys, which were mostly all wooden. But these innovations would have been of little use without wound steel piano wire and the cast-iron piano harp. That is why these innovations appeared alongside the appearance of iron and steel in piano-building, and not before.

As for why things stopped at low "A" for everybody but Bösendorfer, it's because of the hard limitations of the physics of the materials and the technologies that have been invented. None of this has substantially changed since about the 1870s. Physics is physics. The low "A" was the lowest note that was technologically feasible. It sounded good, and the piano-buying public was willing to pay for it. It hit the "sweet spot" between technology and commerce. Only one company in 125 years, Bösendorfer, was willing to go lower than that. Every other piano manufacturer found it unfeasible and commercially non-viable, and they still do to this day.

Answer 4

When the piano was invented it did not have 88 keys and did not start on A. As composers such as Beethoven starting composing music that demanded a wider range of available notes, piano makers of the day responded by building piano's with an expanded range.

The precursor of the piano was the harpsichord which was not the first keyboard (the organ was invented prior to the harpsichord). Very early keyboard instruments did not have black keys and therefore were not chromatic. The early harpsichords and the pianos that evolved from them only spanned four octaves and started on a C. This is probably due to the first keyboards having only white keys so they worked in the key of C or A minor.

Here is a quote from this article Fascinating Facts ... pianos ... 88 keys?

According to piano historian and registered piano technician Stephen H. Brady, medieval stringed instruments originally included only the white keys of the modern keyboard, with the raised black keys added gradually: “The first fully chromatic keyboards [including all the white and black keys] are believed to have appeared in the fourteenth century.”

Before there were 88 key pianos the 85 key piano starting on A became the norm. From the same article quoted above:

Michael Moore, of Steinway & Sons, theorizes that it was a combination of artistic expression and capitalism that gave rise to the 88- key piano. Great composers such as Mozart were demanding instruments capable of expressing the range of the music they were creating. Other composers piggybacked on the expanded range provided by the bigger, “modern” pianos. Piano makers knew they would have a competitive advantage if they could manufacture bigger and better instruments for ambitious composers, and great changes were in store between 1790 and 1890, as Stephen Brady explains: By the end of the eighteenth century, toward the end of Mozart’s career and near the beginning of Beethoven’s, piano keyboards had reached six full octaves, and a keyboard compass of six and a half octaves was not uncommon in early nineteenth-century grands. For much of the middle to late nineteenth century, seven full octaves (from lowest A to highest A) was the norm.

Okay - so now we know why the piano keyboard grew larger over time.

EDIT: And Wheat Williams did a great job (in his new answer) explaining how the technology of piano building evolved to make this expansion possible in order to meet the demand & desire for more notes.

But why did the piano builders all decide to start making the first key on the keyboard an A? Was it arbitrary? Was it a result of limitations of human hearing or engineering? Or was there some logic applied to the decision to start with A?

None of them are around to tell us for absolute certain - and whoever they told when they were alive apparently did not write it down. So all I can do is offer a very logical reason why starting with A became the accepted norm.

When the concept of assigning letter names to identify musical notes was presented in the first century, it only made sense to start with A as the name of the first note. This naming of notes using letters predates the building of many instruments.

Eventually the note that was identified by the letter name A became common to the tuning of most (if not all) stringed instruments. Thus the A note became the reference note for tuning of all modern instruments in an orchestra.

In the early days of keyboard instruments, there was no standardized universal tuning reference that was adhered to. An organ in one church may have been tuned to a different pitch than one across the street.

Along about the same time in history that piano builders started expanding the range of their pianos, there came a coordinated effort to standardize musical pitch. From a Wikipedia article on "Concert Pitch" -

the French government passed a law on February 16, 1859, which set the A above middle C at 435 Hz.[2] This was the first attempt to standardize pitch on such a scale, and was known as the diapason normal. It became quite a popular pitch standard outside France as well, and has also been known at various times as French pitch, continental pitch or international pitch

Piano tuners of the day (in the absence of modern digital tuners) used tuning forks which were tuned to A.

They started with the A above middle C (which is what the tuning fork was tuned to sound) and tuned the other A notes using octaves. The 85 key piano became the standard before the modern 88 key piano did. There are still some old 85 key pianos around. The 85 key piano that was adopted by the piano makers of the day as the standard configuration spanned seven octaves and started on A0 and the last key was A7.

This is very logical from a practical point of view given that the piano tuners of that time started with a tuning fork tuned to A = 435 Hz (this was later changed and now is A=440 Hz) and then tuned the other A's by ear using octaves.

So it stands to reason that if we were going to build a piano with an extended range that satisfied the composers of the day and wanted to span 7 octaves (close to the limits of humans ability to distinguish notes) and if we knew that to tune that piano we would be starting with a tuning fork tuned to A above middle C and work from there - it only makes sense that we would go as far as we could in both directions to cover most of the effective range for human hearing. And to do that it makes the most sense to proceed in octaves for the sake of simplifying the tuning process.

If we start in the middle on A and expand from there in both directions, we end up with a keyboard that starts and ends on A. So there you have it!

Later the 3 keys were added to the end (to end on C) perhaps to complete the C major scale on the last octave.

Answer 5

A0 is not chosen consciously but is just an arbitrary note as a result of natural selection through the ages of practice by composers, performers and makers. It seems lower A0 stands at the threshold for majority of composers and performers to express themselves comfortably, and for makers to build instruments efficiently.

Some points that should be considered are:

• When the frequency goes lower and lower it becomes harder for human hearing to distinguish notes from each other and the notes starts to sound more percussive than melodic. That makes low frequency notes impractical for harmonic and melodic use.
• It gets harder to stop lower notes on piano due to the high momentum caused by the increasing string weight and energy. After some point it is impossible to play bass notes without preventing notes blending into each other. Blending bass leaves no harmony, audible melody nor percussive rhythm behind.
• Earlier pianos were more percussive with less sustain.
• Existing low notes around A0 are used rarely for harmonic and melodic function in the piano literature.

Makers enhance their instruments to increase their capabilities but there is no point in investing time and effort on making them if no one is using it or the maker doesn't find the tone quality well enough. There is a custom made extended range version of almost all instruments (such as Octobass) but the ones used rarely became extinct or only the composers and performers with enough resources could afford them.

A comparison with an instrument with a narrower keyboard, harpsichord may help the discussion. Composers used the whole range of harpsichord extensively and for the same melodic and harmonic function as the other keys. Therefore composer's were limited due to technical limitations.

But for piano, composers usually save low notes for different tonal colors and special effects. It is not possible to make a consistent harmonic and melodic use out of low notes due to incapability of human hearing at that low frequencies. That's why I pointed out the percussive nature of low ranges. We tend to hear them as noise. Although different in pitch, in practice, one key functions similar to the key next to it. There is no point in ivesting more of them after some point. Surviving the ages, that balance point is apparently A0.

Answer 6

The reasons are partly historic, and partly connected with the sizes and design constraints of pianos. There is a compromise between storing enough energy to generate a strong, sustained tone, and having the overtones of the strings in tune with their fundamentals. [The problem is particularly onerous for pianos because they are percussion instruments].
There are a number of requirements for having overtones and fundamental in tune:
The straightforward way is for the restoring force on the string to be entirely due tension and for the bridges at the ends of the string to move a relatively small amount. Unfortunately the thicker strings that are needed to provide a strong sound are quite rigid, and the rigidity provides restoring force. This is physically exacerbated at low frequencies by the limited length of the strings on most pianos. The rigidity problem can be ameliorated by adding windings around the strings, but this has limited benefit at the lowest frequencies on the piano (approximately A, Bb and B). Theoretically one might compensate by winding the string in a suitably uneven fashion; however, I have yet to hear an instrument less than 9' long that delivered correct pitching for either the A or the Bb.
The problem is exacerbated by the reducing sensitivity of the ear aat low frequency: the beat notes between the harmonics are heared equally strongly to the fundamental; obviously this further degrades the perception of the quality of the low notes, and this doubtledd dicourages many attempts to further extend the range.
Bosendoefer and Stuart and Sons are two manufacturers that build large enough pianos to give pure bass sounds and that extend the range down to the E below the usual A.

Answer 7

Yes. Everyone were talking about the evolution, human hearing range, etc., and they are all 100% correct!

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However, there is still ONE REASON that no one has ever listed; and it is the most important reason why.

The reason why the piano normally starts on A while ends on C is because of the very, very strict and strong importance and usefulness of the key of A minor and C major.

The key of C major and A minor are the two of the most common keys in tonal music; and is the most common key that is used in various examples of harmonic theories. This is because they both have no sharps or flats. This means that if we play the key of A minor or C major on a piano or other keyboard instrument, we would usually play only white keys.

Here is Dom's comment that I have recently got in one of my posts:

C Major/ A minor are diatonic and do not have any accidentals. If you are suggesting chord with accidental they are not diatonic.

In fact, they share the same key signature - no sharps or flats. A pair of two keys that share the same key signature are called relative keys. One will be major, while the other will be minor. Therefore, C major and A minor are relative keys.

If we play on white keys, it is easier for us to play a large amount of notes more smoothly. This is because black keys are higher and farther than the whites. Therefore, if we play either only black keys or both whites and blacks, it becomes easier to play wrong notes; and it even causes a bigger chance of straining fingers as well!

Major keys have a brighter sound while minor keys sound darker. If you play C major on a piano, you can both play smoothly and have a bright sound. On the other hand, if you play the key of A minor, it becomes smooth, but dark.

High notes are to major keys as low notes are to minor keys. The highest note of a piano is a C, while lowest is an A. If you play C major, you are likely to play the highest note of a piano. If you play A minor, you are likely to play the lowest note of a piano. This means that it helps us to emphasize the mood of a piece we are playing, without straining our fingers or making mistakes. That is the most important reason why the piano starts with an A while it ends with a C.

Answer 8

An important clarification of the piano base register and the lowest notes.

Whilst the lowest note on the standard grand is A0 with a frequency of 27.5 Hz in fact the piano does not radiate these frequencies to an audience more than a meter or so from the sound board. This is because the wavelength of sound at 27.5 hz is ~12.5 meters. A concert grand with a sound board of 2.5 * 3.5 meters is far to small for it to radiate the fundamental base notes very far as the sound pressure generated from the upper side of the sound board is in opposite phase to the top so the wave cancels itself.

This is the same problem that occurs with loudspeakers for bass reproduction, which is why they have to be installed in a sealed box or a ported box tuned to the speakers resonant frequency.

With close microphones (less than 1 meter from the soundboard), which have a low enough frequency response (< 20 Hz) and with speakers having a low frequency response the fundamental frequencies of the piano low notes can be reproduced at distance.

What you are hearing when the lowest note is played is the mostly the third harmonic which is A2 at 110 Hz. This s a wavelength of 3.8 meters.

The A0 and A2 notes when played even though the lowest frequency is effectively the same the two sound quite different due to the difference in harmonic content.

For un-mic'd concert grands in a concert setting it is impossible for the audience to hear much below 150 to 200 Hz from the piano. They hear only the high order harmonics of the bass register.

Maybe someone should build a piano that had a large space under the sound board with a tuning port so that the low note fundamentals would carry to the audience. I reckon it could be done, but it would change the sound of all notes, mostly by reducing their loudness.

I'd like to see that!

Maybe the big vertical pianos could do this.

Answer 9

Because a G# down there is below the range of human hearing. You will only hear overtones and not the fundamental bass note.

In my experience, only rarely do I hear the fundamental bass note of the first few keys of the piano.

Possible explanations are:

The room is not large enough for the wave to develop

The piano itself is not large enough to acoustically resonate in a way that would amplify the fundamental to a level loud enough to hear