Ivan Mueller (1786 Reval, Estonia ? 1854 Bückeburg - correctly spelled Iwan Müller) was a clarinetist and inventor who at the beginning of the 19th century was responsible for a major step forward in the development of the clarinet, the air-tight pad.
Müller was born in Reval (now called Tallinn), at that time a German-dominated city within Russia. He became a chamber musician in Saint Petersburg before he was twenty. At the same time, he was constantly striving to improve the clarinet, with new types of keywork. At the time, the standard clarinet used flat brass plates covered in soft leather to cover the toneholes. Since these leaked air, the number of them had to be kept to a minimum, which meant that notes outside of the main scale of the clarinet (accidentals) had to be obtained by complicated fingerings which were difficult to play quickly and rarely were in tune. Clarinets would have five or six keys, the bare minimum to obtain an acceptable chromatic scale.
Müller's solution was the stuffed pad, originally made of kid leather stuffed with felt. These pads would 'bulge', such that in combination with countersunk tone holes, would close the keyholes sufficiently tight to permit the use of an increased number of keys making the 'clarinette omnitonique' possible.
Müller went on to work in Dresden, Berlin and Leipzig, where he specialised in the basset-horn, a type of low-pitched clarinet.
In 1809, Müller performed to great acclaim on a clarinet made to his own specifications. Müller moved to Paris, got a wealthy patron in the form of M. Petit, and started mass producing clarinets.
In 1812, Müller presented his new 13-key clarinet with air-tight pads to the Paris Conservatoire, but they weren't impressed. Nevertheless, Müller's new clarinet with fully chromatic range became popular and became the standard clarinet for much of the 19th century. It was further developed into the Öhler system, the prevalent system in Germany today. (Hide extended text)...(Read all) Source : Wikipedia