 During the nineteenth century, a number of experiments were made in adding valves to the natural horn to enable it to play chromatically without the need for hand-stopping.These experiments included adding piston valves (as used in modern trumpets) to a single F horn.The horn was still crooked, by inserting other tubing, to re-tune the instrument for music written in base keys other than F.

The Vienna horn uses a unique form of double-cylinder valve associated with the Viennese firm Uhlmann of the 1840s known as a pumpenvalve.