This seems like a good time to examine the history of the piano. The pianos played by the composers of the Romantic era had evolved considerably from those played by Mozart and even Beethoven. This page will give you a sense of that historical development.
History of the Piano
The piano was founded on earlier technological innovations that date back to the Middle Ages. By the early Baroque there were two primary stringed keyboard instruments: the clavichord and the harpsichord. The invention of the piano is credited to Bartolomeo Cristofori (1655–1731) of Padua, Italy, who was an expert harpsichord maker, and was well acquainted with the body of knowledge on stringed keyboard instruments. The instruments of Cristofori’s day possessed individual strengths and weaknesses. The clavichord allowed expressive control of the sound volume and sustain but was too quiet for large performances. The harpsichord produced a sufficiently loud sound, but had little expressive control over each note. These tonal differences were due to the mechanisms of the two instruments. In a clavichord the strings are struck by tangents, while in a harpsichord they are plucked by quills. The piano was probably formed as an attempt to combine loudness with control, avoiding the trade-offs of available instruments.
Cristofori’s great success was solving, with no prior example, the fundamental mechanical problem of piano design: the hammer must strike the string, but not remain in contact with it (as a tangent remains in contact with a clavichord string) because this would damp the sound. Moreover, the hammer must return to its rest position without bouncing violently, and it must be possible to repeat a note rapidly. Cristofori’s piano action was a model for the many approaches to piano actions that followed. His early instruments were made with thin strings, and were much quieter than the modern piano, but much louder and with more sustain in comparison to the clavichord—the only previous keyboard instrument capable of dynamic nuance via the keyboard.
Cristofori’s new instrument remained relatively unknown until an Italian writer, Scipione Maffei, wrote an enthusiastic article about it in 1711, including a diagram of the mechanism. This article was widely distributed, and most of the next generation of piano builders started their work due to reading it. One of these builders was the organ builder Gottfried Silbermann, who showed Johann Sebastian Bach one of his early instruments in the 1730s. Bach did not like it at that time, claiming that the higher notes were too soft to allow a full dynamic range. Although this earned him some animosity from Silbermann, the criticism was apparently heeded. Bach did approve of a later instrument he saw in 1747, and even served as an agent in selling Silbermann’s pianos.
Piano-making flourished in late 18th century Vienna. Viennese-style pianos were built with wood frames, two strings per note, and had leather-covered hammers. Some of these Viennese pianos had the opposite coloring of modern-day pianos; the natural keys were black and the accidental keys white. It was for such instruments that Wolfgang Amadeus Mozart composed his concertos and sonatas, and replicas of them are built today for use in authentic-instrument performance of his music. The pianos of Mozart’s day had a softer, more ethereal tone than today’s pianos, with less sustaining power. The term fortepiano is now used to distinguish the 18th-century instrument from later pianos.
In the period lasting from about 1790 to 1860, the Mozart-era piano underwent tremendous changes that led to the modern form of the instrument. This revolution was in response to a preference by composers and pianists for a more powerful, sustained piano sound, and made possible by the ongoing Industrial Revolution with resources such as high-quality piano wire for strings, and precision casting for the production of iron frames. Over time, the range of the piano was also increased from the five octaves of Mozart’s day to the 7⅓ or more octaves found on modern pianos. This growth can be heard over the course of Beethoven’s career. Beethoven’s later piano works feature a wider range of pitches than earlier works as the instrument’s pitch range grew. To understand the impact of this expansion more clearly, a numeric illustration may be helpful. A five-octave piano would have roughly 60 keys, while today’s pianos generally feature 88.
Technical innovations continued to be added to the piano as various instrument makers experimented with ways to improve the instrument’s mechanical function and tonal expression. By the late 19th century the piano had evolved into the powerful 88-key instrument we recognize today. It is important to remember that much of the music of the Classical era was composed for a type of instrument (the fortepiano) that is rather different from the instrument on which it is now played. Even the music of the Romantic period, including that of Chopin, Schumann, and Brahms, was written for pianos substantially different from modern pianos.