Clarinet systems

Above top to bottom: Comparison of clarinets – Iwan Müller, Eugène Albert, Oscar Oehler and Theobald Boehm.

Not all clarinets are the same

Clarinet systems refer to the different mechanical designs of the instrument, with the two main types being the Boehm system and the Oehler system (also known as the German system). The Boehm system, with its complex key and ring mechanism for easier fingering, is the most widely used internationally, while the Oehler system is prevalent in Germany and Austria and is known for its more complex fingering and “somber, subdued timbre”. Other systems include the Albert system, used in traditional folk music and for Dixieland, and the Reform Boehm system, popular in the Netherlands.

Key Differences

Fingering & Mechanics
The Boehm system was designed for easier fingering, incorporating more keys and rings. The Oehler system is an evolution of classical designs with a more complex keywork and fingering system.  
 
Sound & Timbre
Boehm clarinets generally have a bright, flamboyant sound, while Oehler clarinets are known for a somber, subdued timbre.  
 
Usage & Popularity
The Boehm system is the international standard, except in German-speaking countries. The Oehler system remains popular with German and Austrian musicians.  
 
Identification
You can often tell the systems apart by their keys: the Boehm system uses “rollers” for the little fingers on the long keys, whereas the German (Oehler) system uses levers instead. The Oehler system may also have a more complex key structure, with some models featuring more keys and rings (e.g., 22/6).

Other Systems

Albert System
A simpler system that features unkeyed tone holes, making slurred passages easier to play. It is still used in some folk music, such as Klezmer and Dixieland, and in parts of Eastern Europe.  
 
Reform Boehm System
A variation of the Boehm system that is particularly popular in the Netherlands