The pianoforte was a direct development of the fortepiano: a keyboard sets in motion a mechanism which strikes the string with a hammer. The defining change that separates the two was the move towards an iron frame. Broadwood started using metal tension bars in 1808 and in the 1820s iron bracing became more and more necessary to ensure the instrument’s ability to cope with the increasing tension of the strings.

The earlier wooden frames would have collapsed under the strain. In addition, the old-style fortepiano could not withstand the new way of performing, with its greater emphasis on ‘attack’ and drama. Now that the frame was stronger, makers were able to try using heavier hammers and strings. Hammers had long been covered in a thin leather jacket. With the new mechanism, there was a risk of an ugly clanging sound as the hammers hit the strings. To avoid this, makers moved away from using leather and tried out thicker materials that would work in the more demanding mechanism: felt became the norm.

Double-Escapement

The escapement action had been an essential element in the fortepiano. It had meant that if players hit the key once, they got one note only: with a hammer action there is always the risk of a rebound, which would produce a faint echo of the original note, ruining the clarity. As the instrument became more powerful in the early nineteenth century, it grew heavier and slower. Rapidly repeating a note was no longer possible, as the key was so slow to return to its original position. The firm of Erard developed a complex system of levers called a ‘double-escapement’ action. This kept the hammer itself at a certain height even while the key was returning to its starting position, which meant that players could hit the key a second time and get a repeated note without waiting for the key to come back up.

Steinway

The Viennese and English actions were in competition throughout the nineteenth century. Eventually it was the American firm of Steinway which, working from the English model, produced a piano with a split-level design. Here the bass strings were built to run diagonally across the treble strings, rather like playing cards when you hold them in a ‘fan’.

In 1859 the firm produced a piano that combined double-escapement, an iron frame and overstringing: this was the modern piano, and although some firms disliked it and were slow to adopt it, this was to be the design that all modern concert grand pianos would eventually follow.

Performance | Rise of the Virtuoso | Early Romantic | Classical