Charles Trute was one of the first

piano makers in London along with

Zumpe, Pohlmann, Backers and a

few others. The earliest surviving

instrument from him is a dated 1771

with a compass of four and half

octaves. There are several square

pianos made in London and and

the USA but also a double manual

harpsichord from 1794. He was one

of the few English makers who made

pianos with tangent action.

Trute’s address was located within

two blocks of one another—on

Broad Street with piano makers like

Beck, Kirkmann, Ganer etc.
He also had a collaboration or

probably made pianos for

John Bland. On a Bland

square piano there is a signature

of Trute to be found.

He entered into a partnership with Diedberg in Philadelphia (probably from around 1788 to 1795). They advertised their harpsichords, grand and square pianos.
Not long after 1795 he moved with Wiedberg from Philadelphia to Wilmington, Delaware (where his name boards bear the title ‚‘Carolus Trute/Wilmington’’)
; there Wiedberg died and Trute ended his days as an innkeeper in 1807. At the of his life he was an innkeeper.
In the New-York book of price of manufacturing piano-fortes page 40 it is marked that the iron or brass hitchpin plates were first used from 1781 onwards on English square pianos by Trute.

Tangent Pianos

The present piano is the only tangent piano by this maker and one of the 4 English pianos in total (worldwide) having the tangent action.
The tangent action is -like the English actions- a so called ’’Stoss Mechanik’’ which was widely and solely used in England (unlike Germany and Austria but also the east part of France where Stoss and Prell actions both were used) but the hammers that hit the strings from below are pivotless and jump freely in the air, guided in a register.

The tangent piano or ''Tangentenflügel’’ is a terminology used for pianos with this action but this name is mainly linked to Spath & Schmahl from Regensburg who made doubtless a great number of this widely popular instrument that was introduced by Spath around 1750 ( decades before in France and Germany others also wrote about this new invention but remained obscure and almost unknow).
Spath made the action with an intermediate lever which made the player play easier with less need of an attack of the finger tips. The older almost unknown tangent action patents were mostly only pivotless tangents which jumped into the strings like harpsichord jacks without the help of the intermediate lever.
This type of instrument was meant to sound like a harpsichord with jacks hitting the strings (bare wooden) instead of plucking. The advantages were :

-Piano & forte sound to some degree 

-Being needless to any adjustments which made life easier for the owners. (harpsichords and fortepianos specially those with escapement like Cristofori/Silberman, Stein/Walter or English grand or square piano's double action and all other later pianos need adjustments time to time while a tangent piano or a clavichord basically needs no adjustment for the action.)
Spath did use these jacks as pivotless hammers but with the intermediate lever the touch became much easier to play and the action was much more serious and reliable. He always left the tangents bare wooden and added several hand stops and knee levers to imitate the sound of other instruments of the period that were also very popular like the regular fortepiano and harp.
Several makers known to us but maybe many more imitated Spath & Schmahl’s tangent pianos in Germany and Italy but there were also tangent pianos made basically as pianos without several sound effect or imitations (Klangänderungen) so the tangents were covered with leather and even with felts until the middle of the 19th century, about 100 years after the birth of the tangent piano.
In sicily some of these pianos in rectangular form (as we call ‚‘square pianos’’) that had the tangent action with even intermediate lever had not only leather on their tangents but also had had no hand stops and sound effects and even no dampers. More surprising is that they had an extremely unusual compass (F-g’’’) which seems to have worked only for folks music or something easy to play for the region in that era.
From Poland we have an 18th century square piano with tangent action and sound imitations, also limited compass but much more a serious instrument than the 19th century ones from Italy.
In England the 4 known tangent pianos are all square pianos also with the tangent action but with only one sound imitation (harp), with 5 octaves which enables the musician to play almost all music composed in that period and before. The tangents are covered with leather, the dampers are under dampers with a bit more sophisticated system. They are raised to push to the strings from below to damp the resonating strings with a lever that looks exactly like the intermediate lever that is hit from below by a piece of OMH (Old man’s head as it is called in English) to throw the tangents with a much higher speed than hitting them directly.
Conclusion : we have tangent pianos in two forms, grand (in one case upright grand) and square. The grand ones were made mostly in Germany and Italy, the squares were made in Poland, Italy (mostly in the 19th century) and 18th century England.
The 18th century tangent pianos all produce several sounds operated by hand stops and kneelevers due to the bare wooden tangents as a basis except the English square tangent pianos which were covered with leather and only have a reliable action and touch for a serious musician while the 19th century Italian tangent pianos can hardly being compared to the German tradition or delightful sound of the 18th century English square tangent pianos.