“Piano” is short for “Pianoforte” which means “soft-loud” in Italian. This name originated from the original “Gravicembalo con piano e forte” invented by Cristofiori in 1710. The name was used to distinguish the new instrument from previous keyboard instruments such as the harpsichord and organ which would not play a louder note if you hit the key harder. The new technology of using a hammer to strike the string rather than a jack to pluck it was the main innovation.

There were two main difficulties with the new instrument. The first was that it was hard to create an instrument which made a loud enough sound, as in order for a string to sound when it is struck rather than plucked, the string needs to be longer, thicker, and therefore much more tightly stretched to produce the same pitch. This in turn requires a much stronger frame than a harpsichord – and wooden frames were limited in their strength. The second difficulty is in striking a single note repeatedly within a short time. The mechanism which stops the hammer bouncing back to strike the string again while at the same time allowing the note to be replayed quickly is called an escapement, and an escapement which was good enough to satisfy the best keyboard players of the time was not invented until the 1780s – Mozart wrote in his letters to his father that a new escapement had been developed in Vienna which was greatly improved, and it was only from this time that music specifically for the pianoforte was written. Mozart, Haydn and Clementi were particularly responsible for this, and Beethoven took it much further. Composers such as Stephen Storace in England took on the new style, and I think that his music would have been very likely to have been played by Mary Bennet and Jane Fairfax, for example.

So when JA was writing the piano as we know it was in a transitional stage from the original design to the design we know today. By the time Emma was written (where a piano features quite strongly in the plot) the escapement as we know it was fairly fully developed but a solution had still not been found to the problem of building a frame strong enough to support strings which could make a sound which could fill a large concert hall. Frames were still made of wood, although they were strengthened with iron bars in larger instruments.

To distinguish these earlier pianos from modern instruments which have frames made of a single piece of cast iron (a concept invented by the Steinway company in the 1850s) they are often referred to nowadays as “fortepianos” rather than “pianofortes” – though this was not a term used particularly widely at the time. Therefore we would normally refer to any of the piano-like instruments played by JA’s characters as “fortepianos”. Mary Bennet’s instrument in P&P2 is a square fortepiano very similar to the one now in Chawton Cottage – it doesn’t have the shape of a grand piano like Georgiana Darcy’s instrument in the same adaptation, but looks more like a rectangular box on legs with a short keyboard cut into one of the long sides. Georgiana’s instrument is much more impressive and expensive – very similar to the one we saw in Kew Palace on a visit last year.

To appreciate the difference between a fortepiano (i.e. a piano with a wooden frame) and a modern piano, you can’t do better than listen to the difference between the soundtrack of P&P2 and P&P3. The P&P2 soundtrack is played by Melvyn Tan – a famous exponent of playing fortepiano music – on a period instrument, whereas the P&P3 music is played by Jean-Yves Thibaudet on a modern instrument with a cast iron frame. The modern piano makes a much louder and fuller sound, whereas the old instrument has a much lighter and thinner tone.

As to which is preferable – well, the debate goes on. However, the sound that Melvyn Tan makes would have been much more familiar to JA and her contemporaries than the P&P3 soundtrack.

The reference for all the information in this post is Cyril Ehrlich’s excellent book The Piano: A History“published by the Clarendon Press; the last edition I know of was in 1990 and there is a preview of it in Google Books.