Until the piano was invented, musical keyboards were organs or clavichords with very small keyboards and keys that just played at one volume with very little resonance.
The piano was invented by the Italian, Bartolomeo Cristofori, around 1700. He invented the hammer and escapement action, which enabled the piano player to control the volume of each note, as well as repeat the same note very quickly. He also invented a knob that would pull out and lift the dampers off the strings – this is the job that the right pedal on a modern piano does. Obviously this wasn’t very convenient as you had to free up a hand to open and close the knob.
Next, the same thing could be accomplished with a knee lever. This was better, but still clumsy to do during a performance.
Early pianos had around four octaves (approximately 44 notes), which is small compared to today’s standard piano which has 88 notes. Around the mid 18th century, pianos had evolved to five octaves. They kept expanding gradually to include higher and lower notes.
Christofori’s early pianos were made of wood and this meant the strings could not be strung very tight, therefore the sound the instruments produced was quiet. These early instruments were called “Fortepianos”, meaning “loud-soft” but this quickly became changed to the “Pianoforte” which is what we call it today, although it’s usually shortened to “piano”.
Around 1780 Broadwood, a UK company, became the biggest piano manufacturer in the world. In 1815, they invented the metal frame. Gradually over time, strings got thicker and made of stronger material, the keyboard expanded further, the “una corda” pedal was added, allowing a player to play even quieter and the casing of pianos became bigger and deeper, to broaden and deepen the sound output.
The iron frame allowed much higher tension in the strings, therefore producing far greater volume. And at long last, an organ maker named Gottfried Silbermann invented the damper pedal that lifted the dampers from the strings, allowing the strings to continue vibrating, enabling long held notes, and doing away with the clumsy knee pedal.
The piano probably had a hand in the development of the Romantic Era of music. In 1821, Sebastien Erard invented a new action for the piano which combined the very popular English and Viennese designs. This action allowed for even faster repeated notes. Franz Liszt was very keen on Erard pianos. He endorsed the brand and used them whenever he could for concerts.
These days pianos haven’t changed all that much. The digital piano industry has made great strides lately and with the average family not being able to fit a full size acoustic piano, they have become the more popular instrument. Nowadays most digital piano manufactures such as Roland, Yamaha, Casio, Korg, actually have the piano action inside their premium pianos, although there are no strings. This gives a realistic piano feel. If you close your eyes, you might not know the difference!