Musical Box Tuning and Electronic Tuners
By Chuck Walker
I have started to write this note at least three times and each time it came out way too long and with far too much detail. This effort may be no better but here it is anyway. There is so much material and questions to answer on this complex topic that there is easily enough for a workshop at some future MBSI meeting.
Any analytical instrument whether or not it is an electronic tuner or something else like a micrometer is useful to some degree or other. This seemingly obvious statement means only that you must understand the limitations of the tool in order to use it effectively. An electronic tuner can be useful to bring any instrument into approximate tune. Many times this can be done so well that it cannot be improved. But for many instruments like pianos, a well trained ear will improve the tuning by resolving or optimizing the intervals. This will account for the various harmonic differences in pianos and cannot be done easily by using an electronic tuner.
Music boxes are a problem to tune by ear using intervals because the persistence of the tone is very short and not loud. So picking up beats is nearly impossible. It therefore takes a superbly trained ear to tune without some sort of aid. Beatrice Robertson is correct in that combs were tuned in the old days by using a master comb or diapason. Alternately plucking the master and the tooth being tuned results in a tooth tuned to within a few cents of the desired value. This accuracy is for the most part adequate for an instrument where the profusion of notes and resonances sometimes makes it hard to pick out just where the melody really is. The harmonics and partials in a musical box tone also tend to confuse the apparent pitch of many notes. Music box scales are stretched much like a piano is stretched. The degree of stretching is frequently very great and can approach a full step and a half over the six or seven octaves in a musical box. Most examples of a large stretch seem to be found among the older bo es.
An electronic tuner like the stroboscopic instruments made by Conn, Peterson and others reads note values by sensing the frequency and reporting note values in terms of A(440). It is an invaluable aid in tuning a music box but only if it is used correctly. The key is to use the instrument as a measuring device to guide the tuner and not treat it as an absolute standard. My approach which is not unique and is used by many restorers is to measure the note values of all teeth in a comb before any restoration work on the comb itself is done. These data are plotted on graph paper octave by octave after determining the scale of the comb or the value of "Do". The x axis is the note value as recorded by the strobe tuner. You end up with a grid or stack of marks one above the other for each octave on the comb.
The analytical capability of this technique is excellent. You can readily see errors in note values as well as determine the stretching and temperament of the scale of the comb. The best part is that if changes to any notes are needed, they can be fit into the pattern found on the comb when work was started.
Let me emphasize again that the electronic tuner is only used as a measuring device and not as an absolute standard. This may very well be the best way to use it in any situation whether music box or not.
Chuck Walker
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Chuck Walker (cewalker@prodigy.com)
Hopewell Junction, NY |
(Message sent Wed 16 Oct 1996, 03:53:21 GMT, from time zone GMT-0500.) |
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