The Development of Flutes in the Baroque Era
Between 16th and 18th century, the flute was crucially changed. The inner bore hole, which was cylindric before, was transformed to a conical one in the middle and lower joint in 18th century. This change is to be clearly seen in the fingerings shown in flute methods of this time.
The cause of this change of the inner bore hole is not documented. But there is a theory, which gives a plausible explanation. As the finger holes of the flute were positioned in a way which allows the finger to close them, the finger holes had a very small diameter and were positioned in a small distance to the next one. Thus the sound of the flute was not so good. But if you reduce the diameter of the inner bore hole, the relation between diameter and length of the tube is constant and the sound is better.
At this time, flutes were already threepart. To adjust the instrument to the locally differing tuning, each flute came with several middle joints of different lengths for exchange. The six finger-holes had different diameters and flutes allowed to play major scales. The gamut covered a range from d one upt to a three. Whereupon Quantz said, the highest suitable tone was the e three.
Later on an additional hole was appended for playing new tonalities. To close this new seventh hole, the first key had to be constructed. As a result mainly the intonation was enhanced and the gamut was broadened.
A milestone of flute history was the book Les Principles de la Flute Traversiere (1707) of Jacques Hotteterre (le Romain). He is one representative of an important family of flutists.
Around 1715 the flutes were built in four pieces. This idea came probably from France. This way the middle joints were easier to change and working of the flutes was easier for the flute maker.
Between 1720 and 1830 many musicians tried to enhance the instrument. Additional keys and finger holes where invented. Most of the changes led to as much disadvantages as advantages. Thus they mostly were soon forgotten. Examples for those enhancements are the register developed by Tromlitz, a sliding lower joint to adjust pitch. Quantz described a similiar tool in his book Versuch einer Anweisung, the sliding head joint.
One invention of Quantz, the tuning cork, has been preserved until today as well as the prolongation of the flute with the two open keys for c sharp and c.
The bass flute was probably invented in France in 1751. From todays naming conventions it should be called alto flute. Due to the length of the flute, the holes could not directly be closed by the fingers. Thus more keys had to be constructed. If anything, the concerto flutes development might have been influenced by this, too.
Around 1770 there was an attempt to extinguish the fork fingerings by more holes and keys. the attempt succeeded and only the C remained a cross fingering. This last gap was closed by Johann Georg Tromlitz later on. The resulting mechanic was flakey and shakey. To play fast and in pitch was nearly impossible on this instruments. In the end of all the enhancements and additions the flute had eight keys and covered a range of three octaves.
The main disadvantage of the flutes of this time was, that the distance of the finger holes were determined by the span width of the fingers. The dimensions were based only on the experience of the flute maker and in ignorance of any acoustic facts.
The most used material was boxwood, which expanden due to the moisture of the breath. Thus in spite of all technical enhancements the pitch was still bad. Beside this ebony, African Blackwood, maple or ivory was used.
Johann Sebastian Bach first composed for the flute after visiting the opera in Dresden (1730). Probably he listened to a formidable flute player there. But even after this, his works were always written for recorder or flute. Perhaps this was due to the fact, that both instruments were mostly played by the same musician. Nevertheless Bach relied on very talented flutists as his compositions are build in a range including tones above the f three.
The start of the 18th century was a heyday for the flute (called "grand siècle"). Responsible for this height were musicians like the above mentioned Hotteterre, John (Jean-Baptiste) Loeillet and Johann Joachim Quantz. The fact that the flute was loved at the French court made the instrument presentable in all Europe.