As you may know, the Sistine Chapel Ceiling has some years ago been cleaned, and the cleaning has stirred up an international controversy. The cleaned ceiling of the chapel shows colours that have been characterised as Disney like! The colours before are murky in comparison. The reactions have shown conservatism in a most astonishing form because some were adamant that the restoration had ruined the character of the famous ceiling.
I do not want to give an opinion on the value of the restoration. For that one should read the abundant discussions on the topic.
The reason I am starting my philosophy page with this is the following. We are used to traverso flutes that have been extensively used. Each time they have been used they have been wet and dried. A good traverso may have been wet and dried between 5000 and 10000 times!! Wood changes when this happens. We are also aware that only few traverso are extant. On my page Dutch makers an estimate is derived of .5 %! Furthermore many of the extant flutes have been changed to suite later taste. So in all very comparable to the murky ceiling before cleaning.
I am afraid that we are sometimes copying thoroughly worn instruments believing that this is "ORIGINAL". If I hear a performance of the musical offering where the traverso is next to the violin and the violin, whatever, is brilliant in tone character but the traverso is veiled I cannot believe this to be original, however fabulous the player and however much I am nevertheless enjoying the performance. I believe that the traverso should also be brilliant next to the violin. Moreover, small changes with respect to the original make veiled originals into brilliant traverso. These small changes involve a proper mouth hole edge and a few hundreds of a millimeter more or less at the proper places in the mouth hole and the finger holes. From copies of these holes in silicon the changes are not even to be distinguished so they have to be done by ear!!
Making replica's of eighteenth century flutes therefore is comparable with showing the restored ceiling. Of course there is a certain amount of arrogance involved in this goal for the baroque flute because it is very difficult to distinguish between the dirt covering the original and the original itself.
However we can reason from two premises,
-we like the tonal qualities of many though certainly not all,
-the tuning of the originals hardly can have been as bad as most of them are now.
For the tuning properties I have the following reasoning. The top tenon on many originals is conical. If you pull out this tenon as we usually do to tune the pitch it will quickly come loose. So at the time they did not pull out much but rather took another joint. This must have been so because they did not like the change in intonation caused by pulling out more then a tiny bit. So the intonation with the joint completely pushed in must have been very good unlike many originals we have now!!
Here comes another parallel with the murky ceiling: some brilliant modern baroque flute players are so used to the bad tuning of the original being copied and playing in tune brilliantly nevertheless (!!!) that they believe that this is a genuine idiosyncrasy of the baroque flute.
Let us first be clear about the absolute impossibility to make exact copies of originals! The originals are usually not round any more. This in it self is a sufficient reason for not being able to make (payable) exact copies of originals. But the original may be warped a bit, some of the wood may be frayed etc. Let me diverge to the aspect of tuning.
We know much about the theoretical aspects of eighteenth century tuning because it was written down in numbers.
In general I do not believe that the original makers who were probably pretty good with there ears and who knew much about the instruments from centuries of wood wind tuning could not tune as they wished.
One more evidence, the Tassi flute original has the property that except from f and f# and some further minor idiosyncrasies it is tuned such that one can play in tune with minimal compensation, so so to speak blowing straight without all the head or flute turning.
So in the following well tuned implies with minimal compensation being able to play in tune. In tune is discussed in the page on tuning and certainly does not imply equal temperament (so f# low, f high such as to give pure thirds for instance).
The basic idea is that the d2 is the back bone of the traverso and from there all other tones are considered. It therefore is my aim to make an instrument that has the tonal characteristic of the original, stays close to the original, but is "well tuned".
Also the tone quality however may need some changing. I do not believe that the original for example had this particularly bad b1 where with little effort even I am able to make it full and sonorous! Moreover if also the rest of the instrument seems to fall in place I am more convinced that I should give you this change.
Another aspect is the relation of the replica with the original time period. This will be automatically preserved if the character of the original is respected. However there is a certain pressure from the modern player to force the instrument from what ever period to be usable for Bach to Mozart.
In the first half of the seventeenth century flutes were straight bored pipes usually in one or two pieces with six finger holes and a mouth hole. The last quarter of the seventeenth century this changes. Bores become conical and a seventh hole with one key is added. In the beginning of the eighteenth century this is the standard traverso. During the eighteenth century the music and requirements for instruments change. For the flute this implies a change from one key to more keys, four, six an finally in the beginning of the nineteenth century twelve or more. Then the flute is completely redesigned to result in the Boehm machine that we still use as the modern flute today.
Also the character of the instrument changes dramatically. In the beginning of the eighteenth century the instrument has a sonorous lower octave and an often difficult third octave, in particular the f. End of the eighteenth century the instrument is required to have a brilliant second and good third octave, whereas on the one keyed flutes the lower octave often has suffered. This immediately indicates the reasons for the introduction of more keys.
We may say that the development shows a new type of instrument in periods of thirty years. Also the music requires this. Therefore the present "re-designer" of eighteenth century flutes has a choice to make: redesign a certain original such that a longer period of eighteenth century music can be played with it or make instruments with the shortcomings of the period. Some of the properties of original instruments are due to warp, shrinkage or human tampering.
We have to decide therefore to a certain extent how we copy the instrument. An exact copy of the present state most likely does not represent the original. The character of the particular period however should be maintained.
This also implies not going for the "all purpose instrument". I consider the latter as undesirable, and therefore stay very close to the original. I therefore do not pretend to make the one keyed flute that should be used to play everything from Hotteterre to Mozart. You can use them for it, but if you want to understand the effects the composer aimed to achieve, knowing the properties of the instruments you need an instrument of the same period.
It does not mean that the original dimensions all of a sudden are not interesting any more. They are the starting point and basis for any reasoning that will lead to the beautiful instrument we believe the original once was. In practice I always go back from time to time to the original and retry original dimensions if I had decided to deviate.