Why does an older piano have 85 keys?
Well, the piano started out with only about 60 keys. According to our piano historian, the first fully chromatic keyboard have appeared in the fourteen century. This is the time when pipe organs were being played. In about fifteenth and sixteenth century, the harpsichords and Clavichords were popular. From that time, piano was invented. It started with a pianoforte built by Bartolomeo Cristofori, the builder of harpsichord. In 1800, the first upright piano came into existence. Soon other builders created pianos. Number of keys and piano sizes varies. Piano makers had different view on how to build their pianos to advance in the competitive market. Also,composers began to write complicated music pieces that demanded for bigger and better instruments. Great composers like Mozart, had to look for instrument that is able to express the range of the music he was creating. Then the innovation of piano began. In 1850, the piano keys moved 4 full octave to 6 octave. Then the keys reached 85 keys, at the middle to late of 19th century. At that time period the 85 keys, 7 octave from A0 to A7, was the standard piano. This is why the older Steinway pianos have 85 keys.
When did 88 keys piano become a norm?
Our modern piano today has 88 keys, 36 blacks and 52 whites. Except for the Bosendorfer Imperial Concert Grand that has 96 keys. But back then in the mid-of 19th century, there are few piano builders who experiment with 88 keys but it did not become the standard of piano back then. In the mid of 1880’s Steinway and Sons plunge into 88 key pianos and other piano builders did the same to meet the rival specifications. Today, almost all of our modern pianos have this configuration, with 52 white keys and 36 blacks. Expansion of keys according to Michael Moore of Steinway and Sons is a combination of artistic and capitalism that they have to reach up to 88 key piano. So at about 1890’s 88-key piano became the standard of the piano making.
Why end up to 88 keys?
Piano keys had reached its limit up to 88 keys for several reasons:
First, tone should be considered. There is limit to the number of tones that a string can be made to reproduce according to Michael Moore. The expansion of keys can affect the tone, especially the bass notes end where the sound can rattle. Also, there is limit on the tone that the ear can hear. So, 88 keys are about enough for the better quality sound.
Second, size should be considered. For example, the Boesendorf that has 96 keys has reached up to 10 feet in length. Boesendorf builders have reasons for building 96 key piano but imagine how much space that piano can occupy if 96 key piano become a norm?
Number of keys differs depending on the kind of piano. Today, modern pianos have a total of 88 keys and older grand pianos have 85 keys. An advanced player often uses grand pianos to play complicated pieces of music. While beginners use smaller pianos. There are 230 strings in an average piano. Each string is about 75 kilograms of tension that with combined pull of strings may weight up to 18 tons. On the other hand, a concert grand has almost 30 tons of total string tension.
Piano design throughout the late of 19th to 20th century has slight changes. Only, the existence of digital piano is considered the great change in piano history at this time period. It has a complete different weighting system that imitates the weighting of a standard piano. It mimics the sound and feeling of a traditional piano. It uses amplifiers and speakers instead of hammers and strings. Digital piano started in 1980’s. They have either 76 or 88 keys.