The use of simple geometry and the local unit of measurement in the design of Italian stringed keyboard instruments:

an aid to attribution and to organological analysis


Grant O'Brien


This paper is dedicated to the memory of the late John Barnes

who has been, and still is, one of the most important influences on my life and work




          More than half of the 750 or so Italian harpsichords, virginals and spinets which survive from the historical period are unsigned.  Of the signed instruments a significant number either bears a false signature or is falsely attributed, and therefore neither their maker nor the centre in which they were built is known.  The lack of biographical information about a number of the makers of instruments with signatures that appear to be authentic means that we do not know where they lived and worked.  This situation is clearly detrimental to an understanding of the stringed keyboard instrument building tradition in the Italian peninsula where widely different traditions and style of building co-existed. 

          Because the Italian peninsula was divided politically into separate city and church states during the historical period of stringed keyboard instrument making, and because these regions remained to a certain extent individual and distinct, and often isolated from one another, the building of Italian harpsichords and virginals followed somewhat different paths from one locality to another.  This means that, although Italian harpsichords and virginals are superficially similar in a number of ways, there are many features of their construction, stringing, disposition and acoustical and musical properties that are different from one region to the next.  Understanding exactly the extent and nature of these differences will clearly not be possible until the surviving instruments, including the large number of anonymous instruments, are grouped according to the geographical region in which they were built.

          Grouping the instruments in this way, the musical resources of the extant instruments can be related to the music and musical traditions of the regions in which they were built.  This is of course extremely important to the history of performance practice since it makes clear what the musical resources of the keyboard instruments were in each of the different regions and periods.  This helps us to understand what is and is not possible musically based on the surviving instruments.  The study of these regional differences within Italy is of great interest not only to scholars studying the history of early stringed keyboard instruments and the music performed on them, but also to modern instrument makers who are copying old instruments for use in making music in the present early music revival, and especially to the non-scholar musicians playing early Italian music.  The most important hurdle to be overcome in this study is to identify the area in which any given unsigned instruments was made.

          Another aspect of the regional variations in the history of stringed keyboard instrument making in Italy concerns the modifications which these instruments underwent during the historical period in order to bring them up to date.  Sometimes the maker responsible for the modifications is known, but usually he is not.  However, the modifications are just as important to the history of performance practice and to the changing styles, pitch levels, musical resources, etc. as are the unaltered instruments.  There has hitherto been no method of establishing the area in which these modifications were carried out.



The local units of measurement

          During the whole of the historical period of harpsichord and virginal building up to the beginning of the nineteenth century, virtually every large city and major centre in Italy used a differently-sized unit of measurement.  Again this was a result of the political division of the peninsula into separate church and city states each with its own standards of length, weight, fluid measure and currency.  In most of the centres the basic, larger unit of measurement was usually either the piede, palmo or braccio (the passo, passetto and raso were also used[1]) and these were divided into the oncia or sometimes the soldo or the pollice.  Only in the period after the Napoleonic invasions of the Italian peninsula, and therefore after the historical period of harpsichord and virginal building, did the metre replace the various local units of measurement.  Therefore if the unit of measurement used in the design and construction of an instrument can somehow be determined, this can be used, in turn, to establish the centre of its origin.  This is a fundamental procedure, basic to the process of establishing the region in which an instrument originated, and can be a great help in establishing the maker of an otherwise anonymous instrument.

          The ability to establish the unit of measurement used to construct a radically-modified instrument is also basic to any reconstruction of its original state.  The method described below has been applied to the Russell Collection Stefano Bolcioni 1627 three-manual harpsichord[2] which has undergone a drastic alteration to its original case dimensions, disposition, string scalings and pitch from its original single-manual state.  This aspect of the use of the unit of measurement as a powerful tool in the analysis of the alterations to this instrument will be elaborated in a further article.

          Appendix 2 at the end of this article give values of the local units of measurement in the centres throughout Italy where harpsichord and virginal builders are known to have worked.  These are arranged both according to location and also according to the size of the oncia, soldo and pollice, and some of the measurements from these tables will be used in the study of some of the instruments in the subsequent discussion.  Clearly the lengths of the various units of measurement from these tables can also be used in the investigation of further instruments by anyone wishing to analyse them in a manner similar to that described below.



The baseboard layout and design of Italian polygonal virginals

          It is quite clear that any maker of instruments - or any other object for that matter - would have worked on a day-to-day basis using convenient numbers and uncomplicated fractions of his local unit of measurement.  For the plain reason that whole numbers or simple fractions are easy to remember, an artisan would work in convenient units of measurement when he is designing and executing the object he is making.  Because most of the measurements used are, to a certain extent at least, arbitrary there is no need to invoke complicated numbers in their design.  This is clear to anyone who has lived or worked anywhere in much of the English-speaking world where the inch, a twelfth part of a foot, was until recently still being used.  Most of the measurements used by hand-workers, artisans, artists, architects, designers and all of those involved in industry and commerce were based on simple numbers of inches, feet and yards, or on their simple subdivision.

          Only where it is really necessary and where dictated by some rule or theoretical concept would an instrument builder use a complicated or irrational division of the local unit of measurement.  This has been shown clearly from the ground-breaking study made of many types of musical instruments by Herbert Heyde[3].  But what Heyde, and more recently Hubert Henkel[4], have failed to note is that the makers of Italian stringed keyboard instruments, at least, designed their instruments beginning with the baseboard and then worked literally from there upwards.  The instrument case measurements used by Heyde and Henkel to suggest theories of numerology in instrument building have been taken (incorrectly in my view) for Italian instruments from the outside case dimensions including the case-side thicknesses, although not including the added measurements of the upper or lower mouldings.  For instruments built in the Italian tradition where the case sides are applied to the outside edges of the baseboard, the maker clearly began both the design and the actual construction with the baseboard.  It is therefore the measurements of the baseboard that reflect this.  The measurements of stringed keyboard instruments which have been used by Heyde and Henkel, however, take no account of the dimensions of the baseboard before the case-side planks were added, but are instead based on the dimensions of the case after the sides are added, and after the top moulding is added to the top edge of the case sides.

          In contrast, the work that I have done recently in this field and illustrated below shows that the maker began his design by drawing out the baseboard using dimensions which were simple integers or fractions of the local unit of measurement, and the case sides that he then applied to the outer edges of the baseboard were cut to a height also equal to a simple number of units (or units plus simple fractions) of the local measurement unit.  The combination of the fact that the case sides were hand thicknessed and therefore not all of exactly the same thickness (not even from one end of the board to the other) and the irregular geometry of both polygonal virginals and harpsichords, meant that the final outside dimensions of the instrument were totally unrelated to the local unit of measurement used by the maker.  Therefore a maker starting with two identically-dimensioned baseboards constructed according to his design could end up with slightly differently-sized cases after the sides were added to the two identical baseboards.  Similarly it is the height of the case without the top cap moulding that the maker would measure in his local unit of measurement[5].  He would mark out a number of planks all of the same width in convenient units and then cut and apply these to the outside edges of the baseboard.  Experience has shown that even here, the case-wall heights are often slightly less than expected in places where the top of the case has been planed down to equalise the level of the top edges at the corners when these did not match exactly after the case sides were assembled.  It is therefore the maximum case-wall height that corresponds to the makers design and not the average case-wall height.  Similarly the position of the soundboard was located by choosing a simple distance for the top of the soundboard liner relative to the top or the bottom edge of the case sides.  The bottom of the soundboard was therefore not positioned relative to the upper surface of the baseboard, and similarly the top of the soundboard (which was usually of slightly variable thickness for acoustical reasons) was similarly also unrelated in simple units of the local measurement to the position of the top or bottom of the case.  Clearly which measurements were chosen by a maker in simple units would depend on his method of working and especially on the order in which the various operations necessary to construct the instrument were carried out.

          The problem faced by an investigator is to find the unit of measurement used to design and construct any given instrument.  An instrument has many different measurements and it is not at all obvious from looking at these expressed in millimetres what the local unit used to arrive at them was.  Even knowing that the baseboard was constructed using simple units of the local measurement is not, in itself, enough to divine the length of the unit used in its design.  This is further complicated by the fact that, being hand made, none of the measurements of the baseboard or the rest of the case, keyboards, scalings, etc. is perfectly exact.  Any method used to find the unit of measurement must therefore also be relatively insensitive to any inaccuracies resulting from the working methods of the maker.

          I want to show here, first of all, how some of the basic principles used by Italian makers when setting out their design for the baseboards of both polygonal virginals and harpsichords were based on the local unit of measurement.  The method used by these makers is based on the way in which they used a simple geometrical construction to arrive at the corner angles of polygonal virginals, and in a similar way to arrive at the tail angle of harpsichords.  Working in reverse, a study of the measurement of the angle and of the orthogonal components of the sides of these corners enables a calculation of the unit of measurement.  Establishing the unit of measurement used in the design of the instrument can then be used to determine the centre in which it was built[6]. 

          The importance of such a method to the determination of the maker of an anonymous instrument is obvious.  The method clearly does not pinpoint precisely who the maker was, but it does reduce the number of possible makers from the vast breadth of Italian harpsichord, virginal and spinet builders active across the whole of the peninsula to those working in one area or centre.  It thus accelerates greatly the process of an eventual attribution of the instrument..  Once the area in which it was made has been determined, it suffices then to compare the anonymous instrument in question with other similar instruments by known builders from the same city or region.

          I want to illustrate the method that I have developed to arrive at the unit of measurement for both harpsichords and virginals.  First of all I will examine the design of a polygonal virginal by Franciscus Patavinus, and I will then illustrate a simple application of the procedure that I have developed to determine where the makers Marcus Siculus and Ignazio Mucciardi, about both of whom we have no biographical information, worked.  I then want to use the method to establish the unit of measurement used by Stefano Bolcioni working in Florence.  This will be done beginning with the measurements of the baseboards of a virginal and a harpsichord by him, and then the length of the unit of measurement will be compared with the known value of the unit of measurement used in Florence.  Having established the unit of measurement used by Bolcioni I then want, in a subsequent paper in next year’s volume of this Journal, to show how a knowledge of this unit can be crucial to the reconstruction of the original state of the Edinburgh Russell Collection Bolcioni harpsichord mentioned above.  Other methods of determining the local unit of measurement used in an instrument are also then discussed.


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[1] A number of other units of measurement which are too large to be involved in musical instrument making like the canna, cannella, tesa, trabucco, pertica, cavezzo, corda and catena were also in use.

[2] See Sidney Newman and Peter Williams, The Russell Collection and other Early Keyboard Instruments in Saint Cecilia’s Hall, Edinburgh, (Edinburgh, 1968) Catalogue Number 4, frontispiece, viii, 8-9.  The new Russell Collection inventory number of this harpsichord is HT1-SB1627.4.

[3] See:  Herbert Heyde, Musikinstrumentenbau, 15.-19. Jahrhundert.  Kunst Handwerk Entwurf, (VEB Deutscher Verlag für Musik, Leipzig, 1986).

[4] See:  Hubert Henkel, Besaitete Tasteninstrumente.  Fachbuchreihe das Musikinstrument, Vol. 57 (Verlag Erwin Bochinsky, Frankfurt-am-Main, 1994).

[5] In the North-European tradition where the case sides are much thicker than in Italian practice, the top moulding is often cut into the wood of the case side itself, and the case sides are usually (but not always) applied to the top of the baseboard.  It is therefore the case height less the thickness of the baseboard that the maker would measure out using a simple number of local units.

[6] Denzil Wraight, in his otherwise splendid work on the identification of Italian keyboard instruments, rejects the evidence provided by the local unit of measurement (see: Denzil Wraight, ‘The identification and authentication of Italian string keyboard instruments’, The Historical Harpsichord.  Volume Three, general editor Howard Schott, (Pendragon Press, Stuyvesant, NY, 1992) pp. 66-76).  Unfortunately he seems to discount the whole process of using the local unit of measurement as a method for determining the origin of an instrument on the basis of a quoted example of the confusion that has arisen because of the fact that the Frankfurt and Vicenza inches are fortuitously in the ratio of 3 to 4.

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