From the mouthpiece data that I gathered, I can extract some conclusions regarding national style, in addition to what has been already commented on the reed position discussion.
The following observations are motivated by the next question: what instrumental evidence do we get from the mouthpieces geometry regarding national musical styles?
As we can see in the below graph, in general, English mouthpieces are the ones with the biggest window area. On the other hand, French mouthpieces show window areas slightly bigger than German ones. This last trend could be representative of the preference of French clarinetists to employ wider mouthpieces than the Germans.1
The points in the Netherlands are much more dispersed: this could be a reflection of the geographical situation of this country, receiving influences from France, Germany, and England.
It is true that during the 18th century, the Netherlands had a quite distinct school of instrument making, with typically Dutch features, and the country could compete with France, Germany, or England regarding instrument making.2 Nevertheless, this is not anymore the case as we progress through the 19th century, and the lack of regularity in the graphic could represent this.
The next graphic could seem a cryptic one, but it is veryinteresting. First, I will introduce the concept of the "chamber" of the mouthpiece: the chamber of the mouthpiece is the linking cave between the window and the bore. Therefore, the longer the window of a mouthpiece, the longer will also be the chamber. The graph shows, in the vertical axis, the percentage of the mouthpiece height which is occupied by the window. The horizontal axis, displays the mouthpiece height. Due to the relation between window height and chamber height, it is also representing the percentage of the mouthpiece height which is occupied by the chamber, roughly speaking.
We see that, in England, independent of the date, they have the biggest windows with respect to the length of the mouthpiece. This means they also have the longest chambers with respect to the total height of the mouthpiece. France and Germany show slight individual tendencies, difficult to prove. Nevertheless, it is interesting that the Netherlands is, again, all over the way, maybe reflecting his situation in the middle of the big influences of his neighbors.
Several observations have been pointed out above, like the fact that the window areas in France were bigger than in Germany, and that in England were bigger than in France. Also, that the chamber tends to occupy a bigger portin of the mouthpiece height in England than in other countries, and that the extant mouthpieces from the Netherlands suggest a weak national school of instrument making there.
The graphics shown in this chapter and the chapter below can provide a useful guide to historical clarinet players. They are a tool that can be used to check whether a mouthpiece from a given time and place is an average product of its time, or on the contrary, if it differs a lot from the norm.3
These graphics can also help historical clarinet players to make more informed decisions about the mouthpieces they play on. By taking some measures, it is possible to check how well an unkown mouthpiece fits to a given time and geographical area, and therefore, help us estimate how historically informed are our choices regarding mouthpieces when playing certain repertoire.
In the future, as more data is hopefully gathered, we could be more precise about this topic.
I have some recommendations for future investigations:
On the one hand, it would be interesting to link the above-mentioned national characteristics present in the mouthpieces to the national music characteristics, as well as to composers. Very interesting remarks can appear when linking composers and musical style to the physical reality of the mouthpieces.
On the other hand, I would also suggest using X-ray 3D scanners or the use of micro gauges to get precise data from the interior of the mouthpiece: bore, chamber, etc, in addition to the exterior measures.