Why is the piano in the key of C?

I play the guitar and have dabbled with the piano and this is a question that’s always bugged me. On my guitar it is trivial to switch keys, especially if I use a capo. Why is the piano designed so that the white keys are the key of C? This makes it much harder for neophytes like me to play in different keys. Wouldn’t it have been more useful to have a piano with all the keys the same?

The white keys are easy to hit, because they’re wider than the black keys, and stick out in front. The black keys are easy to hit, because they stick up above the white keys. Make all the keys the same, and something’s got to give.

Besides, with all of the white keys exactly forming one of the major scales, it at least makes songs in that key easy to play. If all the keys were the same, then you’d be perpetually hitting accidental accidentals even in C.

There are some pianos that have a “crank” to shift the entire piano changing the keys (meaning “C” may become “D” or “F#”), and if I had to guess there’s probably electronic keyboards that do the same nowadays for cheaper.

I think you’re getting a little confused though, it’s in the key of C because it means the button corresponding to “C” written on a page sounds as a C. String instruments in general are in the key of C. The instruments that aren’t in C are wind instruments with fingerings, because the fingering corresponding to a written C don’t sound as a C, the reason for this is so players (especially brass) can easily switch instruments and use the same fingerings they’re accustomed to without having to retrain which fingerings mean what note. Even if the keys were broken up differently, it’d still be in C. The only way it’d be in something else is if you had another piano with the same division of keys, but each key sounded a whole step lower but the music was written the same (Key of Bb).

The answer as to why the white keys correspond with the notes in the C scale is because it makes it a hell of a lot easier to distinguish octaves, and just navigate in general, could you imagine finding the note “D” just by looking at an undivided piano? Never mind not hitting the wrong note during a concert because you can’t “feel” your intervals. Muscle memory will help to an extent, but this is also why string instruments have dots and (in the case of the guitar) frets, to tell where intervals are. It’s just not practical for an instrument with such a range to do that. C just happened to be the key with no sharps or flats and sharps and flats seemed like the best way to distinguish keys. Also, since the black keys are raised it makes them easier to hit when you don’t want to hit white keys. I’d also assume some keys and intervals were more common when it was invented so it was structured to make those easier to finger, but don’t quote me on that one.

The more interesting questions I suppose are “why didn’t we just letter from A - L and not have sharps and flats to distinguish strangely like this” or “why is C the one with no sharps? Why not A?” But those are pretty tangential.

My guess: Try playing a chord that includes two notes an octave apart (e.g., middle C and high C.) Assuming you have normal-sized hands, it’s not too hard. Now, imagine if your hand had to span 13 white keys instead of 8.

These are not satisfying answers! =P

Any easy solution would be to have markings on the keys but leave all the keys the same size. On my guitar there are dots on the fret board to denote, for example, the 5th and 12th fret.

If the size of the keys is a problem then make them a bit smaller. Another compromise would be to have alternating black and white keys; then you’d only have to memorize two (piano) key patterns to cover all the musical keys. As it currently is, you have to memorize a different pattern for each musical key. It’s like the design of the piano is made purposefully baffling.

Imagine if your frets were twice as big as they are now, and you had to play some really gnarly chords. Even if you had visual markings on the keys, playing large chords would be impossible unless you had gigantic hands.

Further, making all the keys the same means you have to look at the keyboard to see where you are. A person sight-reading, or a blind guy, needs tactile feedback to know where they are on the keyboard.

Yeah, just to play an octave in one hand on piano, you’d need what is , on the currently sized keys, about an octave and a half reach.

7/12 of the tones are white keys; 8/13 if you count the octave.

I don’t play piano, which makes it extra sickening that Stevie Wonder et al are so uber good at it. Maybe they practice so much that they can’t lose their place. But having some black keys as guideposts must help as well.

You don’t have to memorise a different pattern for each key, it’s exactly the same.

Different collection of notes of course, but that’s a given. But it’s the exact same pattern for every key. Intervals as follows, 0 being the root note: 0, 2, 2, 1, 2, 2, 2, 1.
This is the same pattern whatever root note you use.

Now because of the nature of the acoustic piano, the way they’re built, a key had to be chosen for the white notes. C is a popular key, especially for nursery rhymes and it corresponds with the way musical notation works (having no sharps or flats until you add them to change the key.)
Or…was music notation designed around the piano? In any case, a key had to be chosen for the white notes.

Electric keyboards have the function to change the key so you can play only in the white notes.

But why not ask the same question about the guitar? Why is E, A, D, G, B, E? so common? Why those notes?
Simple answer, is it makes it easier to play the most amount of chords. Same with the piano, it’s the best layout for ease to play in any key. It looks illogical at first glance though, why not have the notes go A, B, C, D, E, F (and maybe add a seventh string, G?) Well, if you try tune your guitar that way, you’ll find chords incredibly difficult to play.

It’s the same principle on the piano really.

Once you get the hang of it, a key is a key is a key, be it white or black, so the piano is not really in any particular key.

There’s a civil rights joke in here… somewhere.

The question of how the piano keyboard came be is actually a fairly good one, but unfortunately, it’s genesis isn’t quite clear.

The piano is of course a fairly recent instrument, and the real question isn’t about it being in the key of C, but rather why is it based on a diatonic scale (rather than a chromatic one), so the question should more properly be: why is the organ keyboard the way it is.

The organ appears to go back to at least roman times. We know that roman organs were controlled by sliders that blocked and opened the pipes. In the early medieval period, these sliders were connected to lever-like keys that were pushed with the hand or fist.

13th century art depicts organs with a very limited range (a little over an octave) and a sequence of identical keys. The limited range of the instrument was due to the fact that wind from the bellow could not be efficiently distributed to many pipes.

These organs were likely only able to play the notes of the diatonic scale. With a limited number of pipes available, this was the best arrangement for playing the music of the times.

Eventually, though, technical advancements allowed the number of pipes to grow. At the same time, changing musical tastes lead to accidentals being added to the existing diatonic scale. These chromatic keyboards had a second row of keys placed above the natural keys. However, as you can see here the layout of the accidentals wasn’t necessarily the same as a modern keyboard.

Eventually, the current layout seems to have been fixed in the 15th century. The size of the keys wasn’t normalized until much later. Here’s a very nice video of Bernard Foccroulle playing a 1688 organ; notice how small the keys are.

Why weren’t the new keys added alongside the existing one? A good reason might be that this would have been confusing for organists trained with diatonic keyboards. Another explanation might be that these new notes were accidentals, and the diatonic scale was still the foundation of the music. Note that the notion of “musical key” hadn’t been invented yet, so transposition was not an issue.

In the 19th and 20th century, some composers, notably Schoenberg, complained about the limitations of the piano keyboard layout. It makes playing in certain keys much easier than in others. It also gives the diatonic scale a central role that some thought archaic. Some have also argued that the layout is not ergonomically optimal.

There were attempts at coming up with a better keyboard. The most famous one was the Janko keyboard invented in 1882. It’s designed so that the fingering stays exactly the same no matter what key you play in. It never caught on, however, for the same reason that the Dvorak keyboard and spelling reform never caught on either: too many people with too much time invested in the old ways.

Classical piano player chiming in here. I’ve found that key signatures with more sharps or flats are much more easier to play in than the key of C. Actually the more sharps or flats, the easier it is to play. When I play predominately on black notes, it is much much much easier to feel my way around the keyboard. Anything halfway challenging that is played on only white keys takes much more practice to be able to play with no mistakes. As others have said, playing only on white keys gives you no tactile feedback.

The only thing that is slightly easier in the key of C is sightreading.

On a hunch, went looking for an electronic version of the Janko keyboard (of which I’d not heard before). Found one called a Chromatone. Kinda fun to watch. Skip the first video.

Great post, jovan.


There are a few chromatone videos on Youtube, but I’d like to see and hear a real Janko piano. So far, I’ve only seen photographs.

There’s no law that says the guitar has to be tuned to those.

Slide guitar is tuned open…either E B E G# B E or D A D F# A D or others.

Though not a slide song, here’s Cat Stevens’ “If I Laugh.” It uses D A D F# A D. I bet it can’t be as easily played with std tuning.

Here’s Steve Miller on acoustic/The Joker:

He’s fingering chords in the key of G…but it’s in the concert key of F. He’s tuned down a step. That gives that nice rattle. It would be a lot harder to get those little riffs if he were in F.

Anyway, you probably could tune the piano up a step, down a half step, etc. Maybe that would alter the tone, giving the rattle you hear in Steve’s guitar when playing strings that are too loose. You could also re-design the “harp” inside.

Ebony… and … Ivory… llive together in perfect …

Dammit, WarmNPrickly, now I’m gonna have that song in my head!

Something to think about: What key are you playing in if you play only the black keys?

An interesting video: Pentatonic Spriituals on the Black Keys

There are transposing keyboards. There was a famous songwriter, can’t think of it right now (maybe Hoagy Carmichael) who always composed on the black keys.

It’s a hilarious question to me, because I took decades of piano lessons and now have taken up the guitar, which makes absolutely totally no sense whatsoever.