Böhm system (clarinet)

The Boehm system for the clarinet is a system of clarinet keywork, developed between 1839 and 1843 by Hyacinthe Klosé and Auguste Buffet jeune. The name is somewhat deceptive; the system was inspired by Theobald Boehm's system for the flute, but necessarily differs from it, since the clarinet overblows at the twelfth rather than the flute's octave. Boehm himself was not involved in its development.

Klosé and Buffet took the standard soprano clarinet, adapted the ring and axle keywork system to correct serious intonation issues on both the upper and lower joints of the instrument, and added duplicate keys for the left and right little fingers, simplifying several difficult articulations throughout the range of the instrument.

The Boehm clarinet was initially most successful in France—it was nearly the only type of clarinet used in France by the end of the 1870s—but it started replacing the Albert system clarinet and its descendants in Belgium, Italy, and America in the 1870s and—following the example of Manuel Gómez, a prominent clarinetist in London who used the Boehm system and the Full Boehm system clarinet—in England in the 1890s. By the early twentieth century, virtually all clarinets used by performers outside of Germany, Austria, and Russia were of the Boehm system or one of its derivatives. The only alteration to Klosé and Buffet's clarinet that has wide currency is the Full Boehm system clarinet which was introduced by Buffet in the 1870s.

The clarinet was an inelegant instrument in the early 19th century despite the eight keys it had acquired. In 1812, Iwan Müller remodeled the instrument and raised the number of keys to 13. Other makers made small improvements to Müller's design, but the Boehm system clarinet represented the first complete redesign of the key system after Müller.

The ring keys Boehm created for his flute gave other instrument inventors the means to devise logical fingering systems that allowed for more physical agility. Ring keys and needle springs were the two major features adapted for Klosé and Buffet's new design. However, they did not incorporate Boehm's concept of full venting. Ring keys virtually eliminated the problems of cross-fingerings. These rings surround the tone holes so that when a finger covers the tone hole it also pushes a metal ring down to a level flush with the top of the hole. The ring, in turn, is connected to a long axle (borrowed directly from Boehm's flute), which then causes another hole located elsewhere on the instrument to be covered by a padded key. As an original invention for the clarinette à anneaux mobiles, Buffet utilized needle springs in order to control the opening and closing of keys mounted on axles. Needle springs are mounted on posts screwed directly into the wooden body of the clarinet and are used for all keys other than those with extremely short pivoting axles, which continue to make use of simple leaf springs attached longitudinally to the underside of each separate key. This is the method of operation of the keys on pre-Boehm woodwind instruments.

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