Woodwind Instrument Pitch Through The Ages
There are few woodwind instruments surviving from before 1500. Modern makers have had to work backwards from surviving Renaissance instruments using paintings, carvings and woodcuts of the period to offer inspiration and encouragement. Of course, the artists were not that interested in providing images that could be used as 'working drawings' and with so much conjecture, makers do not necessarily agree with their competitors' results. Even when one has some iconography to help supply the external shape, one has no information about the details of the internal bore, which are vital when determining the correct tuning systems, nor any evidence as to the appropriate tone colour or pitch.
The older renaissance high pitch for wind instruments, which appears to have been about a'=462 Hz. - a semitone above modern pitch - was replaced, in the middle of the seventeenth century, by a French chamber pitch of about a'=394 Hz., - which is one whole tone below a'=440 Hz. By the early part of the eighteenth century, French chamber pitch, in turn, was superseded by a pitch of about a'=409 Hz. Even where we have surviving instruments, and as we look at later periods there is a corresponding increase in surviving originals, without having a clear idea as to how the instrument should be played (for example, how hard one should blow), determination of pitch will be approximate.
The present day 'low pitch', a'=415 Hz., has little or no historical justification, having been chosen mainly because it is almost exactly one semitone below a'=440 Hz., which is a convenience for the transposing keyboards built into some modern reproduction harpsichords.
Certainly, the difference between the original instruments and the pitches they were built for, and modern reproductions tuned to a=415 Hz. or a=440 Hz. generally requires a complete redesign of bore, hole positions and length. Shortening and/or the crude adjustment of tone hole size or position is generally insufficient to produce high quality instruments working to one of the modern pitch standards.
By the time we come to the classical period, instruments appear to have been made for a pitch standard of between a'=425 Hz. and 430 Hz. with some being playable to pitches close to our modern pitch of a'=440 Hz.
We recommend those interested in reading about the way pitch changed, through time and from place to place, should refer to our music theory online chapter 27.