A piano with a tangent action is fundamentally different to all other pianos. It uses a hammer that is detached from the action, known as a tangent. It is raised vertically to the strings by an action lever whereas all other pianos have a hammer that is pivoted on a hammer rail and is raised to the strings in the direction of an arc by a jack. In both types of instrument, the hammer is “set off” or released so, that it meets the strings under its own momentum. This is essential to avoid the hammer from blocking the sound.
The action of an English tangent piano has two levers of which one raises the hammer towards the strings and the other lowers the under-damper for the note to sound. This may seem complex, but it is actually a very simple design. The feel of the action is more direct with the strings than other pianos.
The images below show the parts of an Engliah tangent action from a square piano by Charles Trute that was made about 1785.
In Germany, both grand and square tangent action pianos were made in the late 18th century and early 19th century. These instruments often had bare wooden hammers but used several stops to create different sounds. Very few pianos were made in England with a tangent action and I am only aware of three examples that have survived, and these are in the form of a square piano.
One extant example, attributed to Charles Trute, is held at the Osaka College of Music Museum in Japan. A tangent action piano by Frederick Beck was restored in the UK a few years ago and is now privately owned. Another example by Charles Trute was in my possession recently and has given the opportunity to write this article.
Charles Trute had his workshop initially at 26 Wardour Street, Soho, London, and in 1782 he moved to 7 Broad Street Golden Square. In the early 1790’s he moved to Philadelphia, United States and continued making pianos.
The English tangent action square piano has the same functionality as the usual English square piano. Unlike German instruments, the English instrument had leather covered hammers and a single lute or harp stop. These instruments was made in the 1780’s and early 1790’s.
The action has a low profile, and this enabled the soundboard to be extended above the action to provide a much larger area. This feature was not adopted in other English square pianos until the 1830’s such as those made by Collard & Collard.
An English tangent action piano can be recognised by the external appearance of the instrument. Square pianos have a nameboard that can be removed vertically allowing the action to be removed but an English tangent action piano has a nameboard slip like that of a harpsichord below a fixed part of the piano case. Removing the slip allows the low-profile action to be withdrawn from the instrument. This can only be done after lifting out all the tangent hammers and the dampers from their respective slots.
The tangent action was a design not suitable for further development in meeting a requirement for increased power and sonority of the instrument. In England the design was overtaken by other technologies in the 1790’s but instruments with a tangent action continued to be made in Germany.
It is possible that there are other surviving English tangent pianos that are unrecognised at present. If you have a square piano or are aware of one, have look to see whether it is an English tangent action piano. If you find one, it will be more valuable than your average square piano.