This is a reconstruction of an instrument type that was intoduced and patented by
Francois Sudre of Paris in 1892. In order to create an instrument with a differend
sound, he added a membrane to the bell that would buzz while the instrument was
played (Mirlton principle). The membrane is mounted in a valve, allowing to disable
the mirlton. Sudre created such instruments from soprane to contrabass tunings, all
in the same long shape ("ophicleide shape"), with the valve engine mounted on the side.
The instruments did never reach any popularity, and not many sudrophones were built,
most likely because they did not match the musical trends at that time. The sudrophones
also had problems with long term playing, or moist ambients; the membrane collects
moist, and gradually stops working.