Boehm System

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The Boehm System is in its original sense a system of keywork for the flute, created by inventor and flautist Theobald Boehm in the 1830s and 1840s. A key system inspired by Boehm's for the clarinet family also is known as "Boehm system" although it was not developed by Boehm himself.

The basic premise behind the Boehm system is that the tone holes, the openings where the various notes are emitted from a musical instrument, should be located at the proper points on the body of the instrument, rather than where they can conveniently be covered by the player's fingers. From the advent of simple wind instruments, these openings could be so inconvenient that some needed to be covered by portions of the hands other than the fingers. And, on instruments not yet adapted to the Boehm system, elaborate work-arounds, such as the lengthy tone holes in the upper, or wing, joint of the bassoon, have to be provided.

While such workarounds can enable an in tune instrument in the case of smaller instruments, large instruments (such as bass clarinets, contrabassoons and saxophones) cannot be so accommodated. Either the tone holes are too large to be covered by the fingers or the operation of the keywork becomes so cumbersome than the instrument is awkward to operate. Generally, the larger the instrument the greater the need for compromise on intonation.

Theobald Boehm felt that a musical instrument would best benefit from a rational approach that would first consider the regularity of the fundamental scale of the instrument, and only once that had been determined were the measures taken to close those holes. He chose the traverse flute as the instrument to test his theory.

In the case of the Boehm flute, Boehm adapted a system of axle mounted keys with a series of "open rings" (called brille in German, as they resembled the type of eyeglass frames common during the nineteenth century) that were fit around other tone holes, such that the closure of one tone hole by a finger would also close a key placed over a second hole.

Through careful experimentation over a number of years, Boehm perfected his take on the flute, with the instrument gradually displacing virtually all other flutes during the second half of the nineteenth century.^[1] While non-Boehm flutes are still made in limited numbers, they are primarily restricted to non-ensemble situations such as folk music, where tuning and regularity of tone are not considered as critical.

Boehm did work on a system for the bassoon,^[2] and Boehm-inspired oboes have been made, but non-Boehm systems remain predominant for these instruments.

[edit] References

1. ^ Baines, Anthony (1991). Woodwind Instruments and Their History. Dover, 320-323. (republication of third edition, 1967, as reprinted with corrections, 1977)
2. ^ Karl Ventzke, Boehm-System Bassoons in the 19th Century