This instrument utilizes the thirteen-key system – the name of this system, invented by German clarinetist and basset-horn player Iwan Müller, came to be known as the  “simple” system. Iwan Müller pioneered the use of stuffed pads over counter-sunk tone holes, and invented the metal ligature in 1817. For another example of a 13-key clarinet, see our Clarinet in A (E 182).

Some of the most important musical developments for the clarinet occurred between 1760 and 1830.

“First, there evolved the classical and early-romantic styles of composition; second, a modern orchestral idiom appeared; and third, composers, players, and makers cultivated the technical and tonal capabilities of the clarinet. Outstanding individual performers often served as an impetus to the musical imagination of composers, such as Gaspard Proksch and Johann Stamitz; Josef Beer and Carl Stamitz; Anton Stadler and Mozart; Johann Hermstedt and Spohr; Heinrich Baermann and Weber; and Josef Bähr or Joseph Friedlowsky and Beethoven. In turn, makers and players contributed additional keys, design modifications, and construction changes to the clarinet.” [4]

Regarding the performance history of clarinets in early 19th century classical music, Carl Maria von Weber’s clarinet Concertino, and First and Second Concertos were very significant. These concertos were written for Heinrich Baermann, who played ten- and later twelve-key clarinets. Following von Weber, at least three composers wrote concertos specifically for Müller’s thirteen-key clarinet. (Reicha in 1815; G. A. Schneider in 1816; and Riotte in 1818).

See von Weber’s Clarinet Concertos Nos. 1 and 2: https://open.spotify.com/album/102tJj2Q8SqX844qwCMvc5?si=LVti5vaBSAOZpwaCXznYvA

See Anton Reicha’s Clarinet Concerto in G-minor (1815): 
https://open.spotify.com/album/7vVQ39DlQ0UCaRrkCsUdJT?si=kKBpqBp8RUSs_wfybRvw9