The Clarinet Family
There are actually a lot differnet types of clarinets. The type of clarinet you are probably most familiar with is the "Bb Clarinet" - this is the clarinet most often used in bands, jazz and orchestras. If you played clarinet back in highschool, this is the instrument you would have played. There are over ten different kinds of clarinets in the Clarinet Family. Additionally, for each kind of clarinet there are a number of different variations in terms of keywork and bore. Let's just say there are a lot of different types of clarinets.
Though this may seem like a lot of instruments, there are actually a few that are missing from the picture. The most obvious clarinet missing from these pictures is the Eb contrabass clarinet (aka Contra-alto clarinet, EEb clarinet); this a contrabass clarinet pitched midway between the Bb bass and BBb contrabass clarinets. The second instrument that is missing is the basset clarinet; it is exactly like the A clarinet except that it has keywork down to a low C (it is made famous by Mozart's clarinet concerto K622).
The other two clarinets that are missing are more obscure. The first is the D clarinet, which is pitched a semitone lower than the Eb clarinet; it is only used for some of the German orchestral repertoire. The other is the tiny Ab Piccolo Clarient; measuring a scant 15 inches long is only used in bands in place of a piccolo in some Germanic countries and Italy.
It should be noted that the clarinets that are played in most of the world have what is known as Boehm system (French system) fingering. In Germany and Austria (and some parts of Sweden) they use other key systems like the Oelher, Clinton, and Reform-Boehm systems. Also worth noting is that the normal compass of the clarinet only goes down to a low E. The alto, bass, and contrabass clarinets will often have their range extended, via additional keywork, to play down to a low Eb or a low C.
More information about the clarinet family can be found at: