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Towards establishing the original state of the three-manual harpsichord by Stefano Bolcioni, Florence, 1627, in the Russell Collection of Early Keyboard Instruments, Edinburgh
an article published in The Galpin Society Journal, 53 (2000) 168-200 by Grant O'Brien |
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The original string scalings of the Edinburgh Bolcioni harpsichord
The single angled scribed line on the baseboard marking the position of the nut indicates clearly that, for the Edinburgh harpsichord at least, Bolcioni intended that there should be only one nut and not two as in the 1631 Bolcioni single-manual harpsichord in Yale University[1]. The position of this line is very clear and unambiguous. The soundboard, however, has many scratched lines and indentation marks made either as construction marks or from bridge pins which have penetrated through their bridge and into the wood of the soundboard. It is not easy to decide by simple observation which of these marks correspond to the original state and which to one of the intermediate states of the harpsichord. A more analytical method is required to decide which of the marks belong to the original state.
In order to resolve the problem of deciding which of the soundboard markings belong to the original state of the instrument, a kind of string-band strip was made of the indented construction markings beside the jackslots on the registers[2]. This was done by using the cheek side of the instrument as a datum line to mark out the position of each of the indented construction marks from the box-slide onto the string-band strip for both registers. Then the marked-out string-band strip was rotated by 180º and the spine side of the instrument was used as the new datum line. In this orientation the markings on the strip then indicated the original position of each of the long and short c and f strings relative to the spine. Holding it perpendicular to the spine and moving the string-band strip across the soundboard area showed clearly and unambiguously that there are similar construction indentations made with a sharp pointed tool on the soundboard corresponding to the register construction marks for the short string positions[3] marked on the string-band strip. Hence Bolcioni clearly intended the strings to run exactly parallel to the spine except for the lowest bass strings which angle away from the spine in the usual way (see footnote 24). The position of the soundboard indentation mark for the note f is now covered over by the present bridge dating from the Franciolini period. The marks for the top notes f2 and c3 are missing altogether since the section of the soundboard in the extreme treble where they once existed was cut away when the three inauthentic keyboards were added. It is clear that none of the observed scratched lines on the soundboard corresponds to the position of the original bridge position, and most of the indentation marks are, in fact, imprints left by bridge pins which have penetrated through the bridges of the numerous intermediate states of the instrument. However, although not marked on the register, a construction mark for the lowest note [here assigned to be G1] also seems to exist[4] on the soundboard. This then locates the position on the soundboard of the bridge pins for the short strings of most of the c and f notes throughout the compass, as well as the bridge pin for the lowest note [G1].
In order to analyse the scalings of the harpsichord, use was made of the diagram of the baseboard of the instrument shown here in Figure 1. The positions of the short strings were projected back into the soundboard area using the rotated orientation of the near register which originally served the jacks plucking the short set of 8' strings (see Figure 5). The positions of the soundboard construction marks were transferred onto the same diagram by measuring their locations using the present front of the instrument as a reference line. These are each indicated by arrowheads beside the bridge line in Figure 5[5]. The distance from the scribed line giving the nut position to each of the soundboard construction marks was then measured using the facilities provided by the drawing programme being used[6]. This gives a c2 scaling for the short 8' string, measured by the drawing by the programme, of 300.9mm. The position of the missing bridge pins for the notes f2 and c3 were calculated assuming Pythagorean scalings in the region from c2 to c3. The position of the covered mark for the note f between the notes c and c1 was assumed to be on a smooth curve also fitted using the drawing programme and the visible marked short c and f bridge pin positions. The missing indentation marks are indicated on the diagram beside the bridge curve with short horizontal lines. These are all shown on the diagram in Figure 5 along with the short 8' string lengths of the c and f notes measured by the drawing programme.
The position of the bridge found from the construction marks on the soundboard forms a smooth curve on the diagram of the baseboard which is quite accurately parallel to the bentside. This is a strong indication that these markings do indeed represent the original bridge position and shape since it is normal for the maker to position the bentside at a more-or-less constant distance from the bridge. The c2 scaling of 300.9mm found using this method is very close to 11 Florentine soldi = 300.8mm suggesting that 11 soldi was the design scaling used by Bolcioni when laying out the construction marks for the 8' short string lengths (see further the graph of the original scalings shown in Figure 7 below.
In a similar way the position and length of the long set of 8' strings was drawn on the diagram of the baseboard of the harpsichord by assuming a symmetrical position of the long c and f strings beside their respective jackslots relative to the marked short-string positions[7] Figure 10 below. These lengths were then also measured using the drawing programme. The same diagram was then further used to find the original plucking points along the strings as seen in Figure 6. It was assumed for this purpose that the plucking directions of the two registers were the same as the original plucking directions of the jacks on the Yale University Bolcioni harpsichord:
Back Row ¬ 8'
Front Row ® 8'
The gap space marked on the baseboard is about 1½mm wider than the combined thickness of the two existing registers, and so two dotted lines were drawn onto the baseboard diagram at positions exactly ¼ and ¾ of the width of the marked gap space. It was then assumed that the near register of jacks plucked the short set of strings at the position of the nearer dotted line, and that the far register plucked the long strings at the position of the further dotted line. In the diagram, for clarity, only the plucking-point distances for the c2 strings have been measured by the drawing programme and indicated in the figure.
Figure
5 - Original scalings and string positions for the
short 8' strings
Three-manual harpsichord by Stefano Bolcioni, Florence, 1627
Russell Collection of Early Keyboard Instruments, Cat. No. HT1-SB1627.4
Figure
6 - Original plucking points for both sets of 8'
strings
Three-manual harpsichord by Stefano Bolcioni, Florence, 1627
Russell Collection of Early Keyboard Instruments, Cat. No. HT1-SB1627.4
The string scalings and plucking points for both sets of 8' strings as measured using the drawing programme are given in Table 3 rounded off to the nearest half-millimetre[8]:
Long
8' Short
8'
String Plucking String Nominal Plucking
length point length string length point
mm mm mm mm soldi mm
c3 157½ 98 150½ 150.4 5½ 80
f2 236 113 225½ 94
c2 313½ 123 301 300.8 11 105
f1 462½ 141 446 121
c1 631 154 606 601.6 22 133
f 960 171 923½ 150
c 1252 183 1215½ 1203 44 162
F 1557 202 1536 180
C/E 1578 204 1557 1559 57 182
[G1] 1624 208 1603 1600 58½ 186
Table 3 - Estimated original scalings and plucking points
Three-manual harpsichord by Stefano Bolcioni, Florence, 1627
Russell Collection of Early Keyboard Instruments, Cat. No. HT1-SB1627.4
The scalings of the short strings, clearly the ones used to design this harpsichord by Bolcioni, are plotted in the graph of Figure 7. A straight line has been added to the plotted scalings which corresponds to accurately Pythagorean scalings based on c2 = 11 soldi = 300.8mm. This graph shows both that the reconstructed scalings obtained in Figure 5 were designed to be Pythagorean all the way from the bass bridge mitre right up to the top note, and that these scalings were almost certainly based in a design by Bolcioni with a short c2 = 11 soldi (or c1 = 22 soldi, etc). Taken together these two facts give added confidence in the accuracy of the reconstruction of the scalings of this instrument.
Figure 7 - The Original String Scalings
Three-manual harpsichord by Stefano Bolcioni, Florence, 1627
Russell Collection of Early Keyboard Instruments, Cat. No. HT1-SB1627.4
The plucking points given in Table 3 result from positioning the line of the nut and the register gap on the baseboard so that measurements in Florentine soldi give their locations relative to the front of the baseboard along the spine and cheek sides (see Figure 1). (In fact, of course, the plucking position is related to which of the two registers plucks to the left and which to the right, and on where in the gap the registers position the jacks and quills.) The line of the nut and the lines marking the register gap slope in opposite directions and this, combined with the irregular transverse spacing of the c notes along these lines, means that the plucking points were not designed to give simple measurements in Florentine soldi. The plucking points result instead from the geometry of the lines drawn out on the baseboard, the plucking directions, and the position of the jacks in the gap, and give irrational and otherwise unrelated numbers when expressed in soldi. However it is clear from the accurately-Pythagorean nature of the scalings, and the accuracy of the lengths when expressed in units of Florentine soldi, that the bridge was positioned by measuring the string lengths out from the nut position at the irregularly spaced c string locations. I find this a very interesting aspect of the design procedure used by Bolcioni, and an aspect which is revealed only by a careful analysis of the use by him of his local unit of measurement.
A comparison of the scalings of the Edinburgh Bolcioni harpsichord with the other Bolcioni instruments in order to try to understand the intended pitch relationship between them proves to be very difficult. For a start the Edinburgh harpsichord is the only Bolcioni instrument which is designed around the lengths of the c strings rather than on the lengths of the f strings. All of the other instruments have compasses going to f3 in the treble and the measurements in Florentine soldi used to mark out the scalings are all based on the f notes. Although the lengths of the c and f strings in a given instrument should have a length ratio for Pythagorean or just tuning and scalings of 4:3, there can be no guarantee that two instruments, one designed using the c strings as the basis of its design, bears this relationship to another instrument which uses the f string lengths as the basis of its design. It is therefore not completely clear what the pitch-relationship between such instruments should be. The 1631 Yale harpsichord has an f2 scaling designed by Bolcioni to be 7 Florentine soldi; the 1629 Edinburgh harpsichord has a short c2 scaling designed by Bolcioni to be 11 soldi. The f2-equivalent scaling of the Edinburgh harpsichord is therefore 11 x ¾ = 8¼ soldi. The pitch relationship between 7 soldi and 8¼ soldi is 284 cents, or about 80 cents larger than a major Pythagorean second, so that it is unlikely that Bolcioni intended these two instruments to sound at pitches a whole tone apart[9]. I have been able to show elsewhere that the difference between iron and brass scalings in a harpsichord which I have attributed to Marco Jadra[10] corresponds to about 265 cents. It therefore appears at first sight that Bolcioni must have intended these two harpsichords to sound at the same pitch, but for the Edinburgh harpsichord to be strung in iron with the Yale harpsichord strung in brass. However, in fact, it is the short strings of the Edinburgh harpsichord which are designed to have a length equivalent to f2 = 8¼ soldi and not the long, critically-stressed strings. This totally confuses any possible pitch or stringing assignment, and is only made more unclear by the fact that the Munich and Leipzig Bolcioni virginals have f2 scalings of 9 soldi and 8¾ soldi respectively[11]. The latter lengths have no pitch or stringing relationship either to one another nor to the 7 soldi f2 scaling of the Yale harpsichord or the 8¼ soldi f2-equivalent scaling of the short strings of the Edinburgh Bolcioni harpsichord. It would therefore appear that clear and simple conclusions can be drawn neither about the stringing materials nor about the pitch relationships which underlie Bolcioni’s design for these instruments.