If you’re in the process of buying a piano or keyboard, you may be wondering what a full-size piano is.
What’s the difference between a keyboard with 73 keys, and a full-size piano?
In this quick guide, I’m going to take you through how many keys are on a piano, why there are that many, and explain why some pianos have less or more.
How Many Keys On A Full-Size Piano?
Before the piano was invented, composers were playing on an instrument called the harpsichord, which sounds like this:
The harpsichord had only 60 keys, which means that everything that was written for keyboard instruments was limited to the harpsichord’s five-octave range.
Similarly, the first piano only had 49 keys and many models that followed came with 60 keys, just like the harpsichord.
The demand for pianos started to rise as composers starting writing music for the piano. But their compositions took them beyond the five-octave range offered on most instruments.
Because composers wanted to make more expressive music, they collaborated with piano makers and manufacturers started experimenting with different ranges.
Piano makers continued to try out a variety of configurations.
In the late 1880s, the seven-octave 88-key piano was created by Steinway. This became the world-standard, and today most modern, full-size pianos have 88 keys.
How Many White Keys Are There On A Piano?
An 88-key piano will have 52 white keys.
There are seven white keys within every octave of the piano – think of the C Major scale, with seven white keys in a row before repeating itself in different octave ranges.
How Many Black Keys Are There On A Piano?
Assuming 88 keys, there will be 36 black keys on a piano. Every octave has five black keys, with at least one white key in between each one.
What’s The Difference Between White Keys & Black Keys?
According to music theory, there are 12 notes in music (the 12-tone Western scale).
The musical alphabet looks like this:
A, A#/Bb, B, C, C#/Db, D, D#/Eb, E, F, F#/Gb, G, G#/Ab
The white keys therefore represent “natural notes” – A, B, C, D, E, F and G – which are whole-step intervals.
Beginner pianists typically begin by learning to play in the key of C, which includes the notes C, D, E, F, G, A and B.
The C major scale, therefore, is made up entirely of natural notes, and that’s part of what makes it easy to play, even for a beginner.
The black keys are half-step intervals. These are known as sharps and flats and sometimes “accidental notes”.
Outside of the key of C, every other key signature contains at least one sharp or flat.
The key of G, for example, includes an F#. This is what the scale looks like:
G, A, B, C, D, E, F#
The key of F, similarly, includes one flat, namely Bb. Here’s the scale:
F, G, A, Bb, C, D, E
So, to be able to play every scale in every key (something every pianist should learn to do), you need to be able to play scales with black keys in addition to white keys.
As you can imagine, some scales use black keys almost exclusively.
Now, to get back to the 12 notes we were originally talking about, they also represent what we commonly refer to as an “octave”.
So, every distinct group of 12 notes is an octave all its own.
As you move higher on the piano (to the right), the octaves get higher and higher. So, you can play higher pitched notes as you move up the piano.
As you move lower on the piano (to the left), the octaves progressively get lower. This gives you the ability to play lower pitched notes as you move down the piano.
With composers often writing for a mix of instruments (e.g. for an orchestra, consisting of a mix of stringed instruments, woodwind instruments and more), it’s important to have this range.
A seven-octave piano would technically be one featuring 84 notes (12 x 7 = 84), but through experimentation, a few extra keys were added and found to be practical.
That’s how we got the standard 88-key piano.
Why Do Pianos Have 88 Keys?
These days, pianos with 88 keys is a given, because almost all piano music is composed within those limits. There is no need for more keys.
Also, the notes beyond those 88 keys are either considered to be too high or too low for the human ear.
We can hear the sound they make, but it becomes difficult to discern individual notes in that range.
It could also be said that higher and lower notes are impractical and unnecessary for most songs.
Do All Pianos Have 88 Keys?
There are exceptions, of course.
First off, Stuart & Sons makes a 102-key piano that costs a mere 220,000 Euros.
Bosendorfer sells a 92-key piano, with each extra key being colored black, so that the pianist can discern them from the regular notes on a piano.
So, while manufacturers continue to push the boundaries, the need for a piano with more keys is minimal.
And, pianos with more keys are longer and heavier, which can also impact their practicality.
So, beyond these weird exceptions, all full-size pianos have 88 keys.
Now, that is not to say that smaller pianos don’t exist.
From keyboards and MIDI controllers to digital stage pianos and synthesizers, other keyboard instruments often have a different number of keys.
Many stage pianos will have 73 keys. 73 keys give you a little over six and half octaves, which is enough to make most music.
Smaller, entry-level digital pianos sometimes have just 41 keys.
Synthesizers that are designed for bass playing or lead playing will sometimes have just 25 keys.
But, if you are buying any sort of acoustic piano (upright, apartment sized, grand) you can expect the full 88.
How Many Keys On A Piano Conclusion
Almost every piano has 88 keys.
If a piano has more than 88 keys, that is highly unusual.
If a piano has less than 88 keys, it is most likely a digital instrument. Less keys makes these instruments less expensive and more portable.