To the consecutive steps in organ the building evolution correspond major trends in the tonal design of the instrument. The scope being France and above all Alsace, the following will be reduced to :
Of course, there a many other styles (Nordic, Spanish, the Italian "ripieno", only to quote some of them).
The French "Classical" organ is a generally medium size (25-35 stops) instrument, with mechanical action (tracker), with a disposition driven by the sound synthesis according to overtones :
These stops are distributed over the divisions is a characteristic way :
The French Classical organ (studied by André Silbermann
during the two years he spend in Paris, working for Thierry) is in fact an "evolution" of
the Flemish organ in the 16 th century. This is especially true for the divisions disposition
(great / choir / echo).
The keydesk of such instruments is integrated in the great case, and closed by two shutters. It is called "Console en fenêtre". A major advantage is that is the best place to put the keyboards when using a mechanical, direct, suspended action, i.e. with trackers and rollers directly linking the pallets to the keys..
The repartition of the stops on the various divisions is done in the following way :
It is the organ in the 19 th century. Marked by Cavaillé-Coll in France and Walcker in Germany. If the word "Romanitc" has a strong meaning in literature, it was used in music for its convenience more than for its precise meaning. In comparison with the Classical organ, an instrument of the "Romantic" period will be characterized by :
The "symphonic" organ is sometimes considered as comparable, or precisely opposed to the romantic type. Its characteristics are :
The keyboards console is generally independent, and equipped with devices facilitating "concert" performances :
There are other distinctive features :
In Germany, the Romantic organ is often characterized by loud stops, and high pressure.
The period corresponding to this tonal design is the first half of the 20 th century. In reaction against some Romantic organs, sometimes not of the best workmanship (but obviously fitting to the industrial ages), and because of the re-discovery of the Baroque literature (above all Bach's) new instruments were wanted, characterized by :
As a consequence, these instruments must have a lot of stops, and thus
mechanical action is almost impossible.
The "universal" organ, able to play "anything" does not exist, can cannot be built. Designing organs able to play any style resulting in building instruments without any style.
It is obviously illusive to think that an organ case designed to shelter 3à stops can contain 60 of them (with larger compasses), with bulky action devices and a lot of additional accessories. Cavaillé-Coll said that "one must be able to turn around each pipe", meaning that the organ has to "breathe".
Neo-classicism lead the Silbermann organ in Strasbourg, St-Thomas to a 60 stops, completely re-voiced instrument, playing one half-tone higher (this had been achieved by cutting the top of the pipes).
When, in 1948, the organ in Strasbourg, St-Pierre-le-jeune had to be re-built, Ernest Muhleisen and Alfred Kern, were both working together at this time, were in front of a work by Jean-André Silbermann, 1780 / Jean-Conrad Sauer, 1820, which had been very much altered (by Wetzel, Roethinger).
This instrument was moved (in year 1900) to a 15 th century jube. Of course, the organ, (in its original cases, 1780 / 1820) had been "pneumatized" and "Romantized".
For Ernest Muhleisen and Alfred Kern, trying to bring together the tonal design
of the organ and its prestigious surroundings (building with parts built in the 13 th century,
Roman tower) was a major concern.
Voiced by Alfred Kern, the instrument marked a real revolution in organ building, soon spreading to the whole France, support by the well-known organist Michel Chapuis, and by other organ-builders.
Ernest Muhleisen had already built a mechanical action instrument (his first work, in fact his masterpiece), in Pfulgriesheim, 1943, in an age when this type of action was completely outdated. Later, this organ-builder took the opportunity to buy the Wetzel stock, rich of many 18 th century stops. This did maybe participate to his decision in St Pierre-le-jeune.
Alfred Kern, once having taken up his own business, built his first organ in Strasbourg, Notre-Dame des Mineurs, 1957, with mechanical action. It is a rather bad instrument, which does not hint that Kern would become the so successful re-builder of the Silbermann in Strasbourg, St-Thomas (1979), but also the builder of the magnificent organs in Paris, St-Séverin (1963) and Strasbourg, Cathedral (1981).
This "Neo-Baroque" style is a bit difficult to characterize. Because the organs in that style are not "Baroque". It was not a come-back to Silbermann's organs, above all not to Gottfried's. These instrument much nearer to Nordic organs. But the great principles were progressively re-discovered and applied.
Then, the organs by Curt SCHWENKEDEL, who was for sure resourceful and inventive, are somewhere between the "Neo-Baroque" and the Italian style.