David Beard

Okay. At last we've introduced the many elements of this Cremona method. Now we can see how these things were used in an actual example instrument. The 1662 Nicolo Amati 'Arnold' violin: Here the instrument is shown with the various framing elements marked in. These include the bout boxes creating lines and an overlap through the mid of the instrument. We also see the treble and bass waist lines, and the nominal waist line running mid of the lap. The center 3rd and i3rd as well as the center 9th are also shown. All of these guides are available to a maker when working soundhole eye placement. In this example, it's helpful to notice that the treble and nominal waists nearly match in level, but the bass waist level is a bit lower. These various waist lines are the main candidate levels for starting the long arc guide that will help place the upper eye. It's very important to realized these Cremona methods are not proscriptive. They do not dictate a fixed process that then determines or provides the placement. Very much contrary to that paradigm, the methods of the tradition are only going to require a bit of traditional structure to the way the maker gets to where he chooses to go. The maker will ultimately decide where the low eyes end up, and where the upper eyes end up. These things together also means the maker is choosing how long or short the overall soundholes end up. The role of the actual methods then is rather limited. What the methods actually do: I) insures the level of the low eye is related o the center 3rd in a way that can be explicitly repeated or varied by specific well defined choices in a later instrument. II) Forces taking some heed of the actual final corner geometry when placing the low eyes. III) the traditional sizing of the long arc guide's radius inures the upper eye placement and overall dimension of the soundholes derives from the waist to low eyes distance. IV) insures the distance from edge to eye is approximately 1/2 the distance from lower to upper eyes Here is the example with Nicolo's soundholes blocked out: Next, we mark in some guide lines om the lower corner work. Some of these are from the edge work, some from the centers of the corner work circles. In this example, the center lines from the outer corner work circles are relatively high. Normally, the low eyes are placed below the corner underturn guideline and above the outer corner circles center line. A maker might mark the underturn guide anywhere they like through the purling. In this case, I've responded to the high position of the centers line by marking the under turn as high as possible. However, in practice, Cremona makers much more often seem to have used the lowest possible underturn choice. After marking guides, I've indicated likely positions for the eyes. The choice of long arc radius can not be arbitrary because 1/2 that radius must also give usable 1/2 arc guides for the horizontal inset of the eyes from the edges. In the net illustration, I posit a possible choice. ' I'm being mindful to support the 'below UB' position Niolo wanted for this instrument's upper eyes. Next, I settle the level of the low eyes by setting the reference line as 2/9 3rd, and the drop circle diameter as 1/2 oncia Lastly, we complete the arc guides and placement of the eyes

I've been trying to find a simple or straightforward way to discuss the placement of soundholes in old Cremona practice, but it jut isn't a tidy or simple subject. So, I'm just going to dive in as best I can. Probably the strongest clue we have, pointing to the general Cremona eye placement method is Strad's three diagrams he made for special case unusual sized instruments he made in the years heading up to 1700. These are the TV, CV, and form b cello diagrams. Unfortunately, the public imagining for these diagrams is of low quality and not clear about exact sizing. Here is the alto viola diagram: As a general idea, Stradivari is not usually the best study example to begin understanding an old Cremona method. Strad comes relatively later in the tradition, and he was very probing in exploring possible variations without breaking the traditional method. Because of his complications and refinement, he's not generally the most direct way to see the basic methods. However, eye placement is the exception. Strad's diagrams show us the main elements of the main methods. Here is the same CV diagram reconciled to the Tuscan Medici alto viola. The next images shows the elements of the diagram clarified as much as possible. Notice that the CV diagram does not closely match the instrument. I don't believe these diagrams were made as direct plans for specific instruments. Rather, I suspect he made these as aids in considering how to apply a successful variation of the general methods in some special instrument types that present challenge for him. There are several elements in this diagram that are basic to the general Cremona methods for the eye placements. 1) The low eye centers sit on a line draw in each of the diagrams. Determining this line is how the vertical level of low eyes is actually set. In real instruments, this level is often set independently on the treble and bass sides. 2) In each diagram, there is a second higher line drawn through the corner turn. In the method generally this line is sort of collapsing two different things. First, there often is a guide line through the corner turn that is considered in a couple ways. But, second, and more significantly, there i always a reference line from which the eye center line is set. Like the center line, this can be independent on the treble and bass side. In a few examples, these reference lines are set low enough to run into the corner work some, bu usually thy are set higher than shown in the Strad diagrams, running clear and above the corners. 3) Each diagram shows he upper eyes centered on an arc I've highlighted in blue. I'm going to call these 'long arcs' in the eye placement methods. These arcs generally start from a point along an important center level, usually the waist. The horizontal placement of their starting point is also important. Usually this relates to the edge work, or the center 3rd framing we considered in a prior post. In Strad's diagrams, he marks the start of these arcs clearly with a point, but he gives no hint to the logic behind his placements. We will learn those things from more general study of these methods. The radius of these arcs i not indicated in his diagrams, but it generally runs from the starting level (usually the waist) to a point either based on th corner guides we will consider or the actual eye. 4) we see horizontal guidance of the eye placement from smaller circle arcs center on points along h edges. Strad's placement of these centers inn these diagrams is not typical of the main general methods. Also, he shows these arcs giving the eye centers. This does happen in many real example instruments, but much more often, these arcs give a boundary that the eye sits against. Also, in real examples, these arcs are generally exactly 1/2 the radius of the long arcs. I will actually rfer to them as half arcs. Strad is not precise or consistent with this in these diagrams. While these 4 main elements are used consistently throughout the Cremona eye placement practices and examples, there is a great deal of ad hoc variation in specifics of the application of these elements when makers work eye placements. These next images show the TV and B forms. Just in these three diagrams we can see how varied Strad is in applying the basic elements. The TV diagram matches the Tuscan tenor comparatively well. The important last thing to note in the TV and B form diagrams is that each of these shows arcs from the reference line that drop down and give the level of the low eye center line. As we will see in the next post, examining the general use of these elements in Cremona eye placement methods. The general way the low level is set is by he combined effect of two choices. One, a reference line is set as a ratio along he center 3rd or i3rd. Two a drop down distance to the eye level is set by choosing a 'drop circle' as a specific oncia size choice. e

It appears to be older and broader than Cremona. Earlier non violin examples from Brescia and Venice appear to use the same unit. Also, various examples from other countries also seem to use the same unit. For example, Henry viii brought six venetin viol Masters dto court in 1540. They seemed to have had a àlaating influence on early English ßvsiol makers, and to have eontroduces this oncia. It appears to be used in William bolles beautiful queen's head viol from circa 1590.

Yes. There has been a lot of confusion,and there are many ways you can try. The point of the article howeveris that not only is 39.75 mm consistent with the clues, like vspra's illustration, but a long list of interesting things pop out at this value that don't for others values. The insets become 1/5 and 1/6 oncia for smaller instruments and 2/4, 1/3, and 2/3 for larger instruments. Also, the instrument types get some simple boundaries for their inner length choices, like under 9 for violins,under 29 for cellos, under 39 for contra basses, under 12 for tenors,and over 19 for contraltos. The sizing of soundhole eyes makes heavy use of diameters 1/4,1/6,1/5, 2/3, and 1/3 oncia Also, the key volute height in scroll work ends up takiing very sensible values like 1 1/4, and 1 1 1/5 oncia.

In my current article in the October 3036 Strad, I conclude that adopting a value close to 39.75mm for the dinstrument making Cremona oncia. Corresponds well with a modulus analysis of many observable patterns is Cremona instrument and wooden forms. Note: I'm not suggesting they swoeked with 3 decimal mm precision, but that is value sitts solidly inside what they did and what we can conserve.

That training data is so far not available for AI. It remains an in person experience available to only a few individuals in the trade.

Yes. There are consistent principles in Cremona methods, but the methods always provide choices and room for makers to steer results. The results can and sometimes do evolve. Not because the principles or methods change, but because maker preferences in the choice aspects of the methods evolve to reflect learning. That is part of why the methods I discuss show a certain kind of complexity. They embrace centuries of development within a quite steady framework of principles. In Cremona, the violin family methods change almost not at all. Just the choice preferences evolve.

Hi Marty, Here is an analysis of the 1726 cornerless Strad. This instrument began as a Viola d'Amore before being converted for use as a violin. For this reason, various details are resolved within the same broad principles, but with some specific details. In particular: 1) the offset between the inner and outer length is 1/4 oncia. This is common enough in violas and sometimes cello. Cremona makers general stuck to 1/5 or 1/6 however with violins. Despite the larger offset, the inner length choice is 8 3/4 oncia, which was very common in violins. 2) The vesici proportion in the lower bout is 5:6:5. This would never be used in Cremona violin work. In violins, the gap between the circle centers is never larger than the radii of the circles. That sort of proportion however is common in different instrument types like the lira d'Braccio. Despite these differences, the relation of the waist and the soundhole eyes to the center 3rd and 9th is pretty much normal. The low cut is a 7/8th of the 2/9 drop from the nominal waist. Which is entirely normal. However, the island width is again different than would be ever by seen in a normal Cremona violin. Use as a viola d'amore requires a wider bridge island than normal for a violin. Here, the difference is achieved by running the island setting rectangle up from the bottom of the center 3rd, instead of from the low cut, which is normal for Cremona violin work. The rectangle proportion is the most common for this task: 1:1 .

We haven't depended or the corners at all yet. But, when we get there, the interaction is with the corners and sides. Basicly, there are other general position principles that relate to the 3rd frame. So no reliance on sides or corners. But, oddly or too closely placed corners or sides can push the positioning around some. My next illustrated post will be in a few days. That will start to address the actual positioning of the lower eyes.

In my research process this was also probably the single most difficult observation for me to accept. I trust you will get there also. Notice that once a maker as marked in the 1/3 and 1/9, you get the 2/9 for free. You've already marked it. You just place your divider on the 3rd and spam it across the 9th. That's your 2/9. The other teo thing that were difficult to initially accept are that the small difference between 3rd and inner 3rd matter. The business of dropping down a partial 2/9 was also difficult. But, these things are necessary to have a consistent understanding across the full range of existing examples. ***** At this point, my research has encompassed a large range of examples. Years back, early in the effort, a built up a spread sheet of over 1500 instruments where there is some public information available. I then collected images for over 900 instrument. I then focused on about 370 were the combination of importance, information, and imaging makes them more useful. My data base of examples that are now scaled to their original oncia and ratio sizings now has over 220 examples. I haven't by any means tested all the methods I believe have been on covered against all examples. I have instead focused my efforts on looking at just enough examples to convince myself of which hypotheses hold and which fail. It's been a very long journey. But, I'm also a very long way progressed from the starting. At some point relatively far into the path, I began to understand that as special as Cremona results were, their methods were not some independent or exceptional invention. Instead, their methods are successful narrowings and specializations of broadly common methods. Shortly after that realization, I broadened my studies to included older iconography. I believe studying the lines of instrument the led to the violin family can improve our understanding.

Okay. Here is the first part of a visual presentation of the soundhole layout principles as observed in Cremona examples (and related methods in Brescia, Venice, etc) This first presentation only covers setting the lower boundary of the soundhole curves ('low cut'), and setting the width of the island the bridge sits on. These two layout elements weren't necessarily set first during Cremona work. But they are the first layout choices that can be set. These two elements can be set, or at least anticipated, before the sides are actual made. It is enough have determined the bout widths. However, it's quite possible that makers did none of this work until after the top plate outline and corners were finished. If so, they could potentially have set the lower eye positions first, and delayed these two layout choices until a bit later. Nevertheless, we will start here. The first two images show the 1665 'Hepton' violin by Nicolo Amati, first analyzed showing its initial layout choices, and then second showing the layout of its 'low cut' and 'island width' choices. The next image just shows some of the elements we will consider in these layouts. Actually, just by setting the length choices for an instrument, we already know many things about the eventual soundhole and center layout. This is because the length immediately also gives us the center 3rd of the instrument and also the center 9th. Both of these are important in center layout. Also, the difference between these, 2/9 of Body, is immediately easily available to us after marking in the 3rd and 9h guides. All these things play roles in laying out the instrument center and the soundholes. While the length alone already gives us expectations of the center layout, to resolve this layout we will also need settled choices for the bout widths and the 'nominal waist'. The bout widths can be taken and measured from the ends of the instrument toward the center to make 'bout box' lines running through the center area. The overlap between these defines a 'lap' zone where the waist was almost always chosen. Deciding a 'nominal waist' is an early design step expressing intention in the design. However, due to the very loose physical process of Cremona making, the actual treble and bass side waist levels usually end up deviating a little, or not rarely a lot. In all the discussion of soundhole layout, we will just say 'waist'. But, in practice, this usually means the nominal rather than actual waist level. However, the makers freely use one or both actual waist levels 'ad hoc', whenever it suits them. The nominal waist choice has a number of things it tends to honor. 1) the waist almost always sits within the bout box 'lap'. 2) strong preference to be near 5/9 of body (top of center 9th), 3) strong tendency to be 'mid' lap. Interestingly, the 'mid' lap and 'near 5/9' preferences don't automatically agree. However, as the tradition progresses, we see a growing tendency for makers to work out the planning of bout widths so that 'mid lap' and '5/9' nearly or completely match. In the 'Hepton', the 'nominal waist' is on 5/9. Cremona method used drops from the center based on 2/9 of the body length to set the 'low cut' guide for the soundholes. In the Hepton examples, Nicolo Amati chose to drop the 'low cut' 2/9th of the inner body length from the LB center level. Of course, we have no way of knowing how he verbalized or conceptualized that choice, but is what is present in the instrument. This idea of 2/9ths drops initially struck me as difficult to accept. It just seems too arcane. However, it turns out to be a very broadly based thing in Italian instrument making. It's seen in various forms not just in Cremona practice, but in other regions, other instrument types, and even before Andrea Amati came on the scene. For example, 2/9th gives the diameter of the round soundholes seen in the Urbino and Da Salo citterns at the Ashmolean. It gives the island width of the Giovanni Maria viol also at the Ashmolean. It's even found used in the beautiful English 'Queen's head' viol by William Bolles in London. This last I found very puzzling when I first noted it. However, it turns out that Henry VIII brought 6 Venetian viol masters to court in 1540. They brought their Italian making principles to England, influencing at least some of England's early viol makers. Once the 'low cut' is set, the maker can set the island width by running a rectangle of set ratio up from the 'low cut' to one of the center levels. In the Hepton, Amati runs a 1:1 rectangle from the low cut up to the waist, thus setting his 'island width'. The last illustration shows the range of variations of these methods seen in the broad picture of Cremona and Cremona related making methods.

Hi Again, I will try to add a fuller response on assymetries in the next several days. Also, I'm sure I full caught your questions above. For now: Physical asymmetry in bending and then pin aligning the sides is physical/emergent. The maker chooses a mold to bent the form, but the physical bending process is loose, and the makers don't seem to value attempting to tighten that control, almost the opposite seems true. It's ass if they placed some significant value on giving the wood a bit of liberty when bending it, or at least that didn't avoid that aspect of the wood. Then, with neck attached and the sides free of the form, they chose the length of the back plate by pinning the upper and lower blocks, then they chose twisting the neck for a straight alignment along the center line. Next, the made choices about bout widths and corner place of the sides by pushing/pulling and clamping the sides into a position. The widths were chosen to support a choice of final plate widths. The corners were chosen, often asymmetrically to support chosen final corner positions having reasonable relation to chosen corner guides (but the choice were ad hoc to accommodate the physical sides actual corners as a last clamped and last set choice. All of this also leads them to physical/emergent assymetries in the actual sides as pinned/clamped and finally etched to the board. A good geometry is then worked on the back board giving a decent overhang relation to the etched sides. In some Brothers and Nicolo Amati work there is a concerted effort to minimize resulting assymetries in actual design choice. But, still there is some responsiveness. The worked back designs respond most in the placement of corner circles to resolve the corner work design. The size of the circles are almost always symmetric bass to treble side, but placements very freely respond to actual sides asymmetrically. The diameter of the primary large arc for the c bout is the next freest response to an asymmetric etching of the sides placement. This choice is first adjusted as diameter equals lower bout versus upper bout. Variations of outer versus inset choices are the next layer of asymmetries. But in late Del Gesu, he goes as far as make different vesici proportion and riser radii choice treble to bass side. This is seen in several of the most beloved and valued violins that have every been made. Assymetric vesici choice is the far extreme of accommodating assymetry in the design choices. With all these things we find that a fair degree of assymetry is often well established in an instruments corners and also shape of the center bout curves by the time SH layout is resolved. Here is where I don't know that t understand your questions. Risers: I only use this label for the arcs rising from the bout lines toward the corner circle work. Occasionally the riser connect directly to the corner circles, but usually there is a bit of straight line tangent join between the riser arc and the first corner circle. These riser arcs are usually equal radii choices from treble to bass side with equal placement related to the edge. But not always. Sometimes the riser choice are assymetric. These tend to be as hoc late choices to accommodate the rest. Risers are not generally equal in the upper versus lower bout systems. With soundhole layout, the half radii guide arcs from the sides are consistentently equal upper to lower, but not always treble to bass side. The most arcane stuff in the entire Cremona methods is the stuff about positioning the soundhole eyes. First, this layout work is related to the 'principal center levels'. This already gets complicated. Theae levels are from the bout box lines and the waist. (draw a box from the end of the instrument around the width of a bout. One side of this box will pass near the center of the instrument). Both the outer border and inset bout boxes are used, and from both the upper and lower bouts. This gives us four bout box lines through the center area: LB, LBi, UB, UBi. The waist almost always in Cremona work is set in the overlap between the upper and lower bout boxes. To make things even more complicated, there are three versions of the waist level. The centers of treble and bass great circles for the c bout each give a waist levels. Sometimes these match, but usually not exactly. Sometimes the levels differ significantly. Thirdly, there is usually a 'nominal waist' idea that these actual levels are approximating. Usually this is either the mid level of the bout box overlap, or sometimes 5/9 up the body length. Very often the makers cause these two to agree. Sometimes the nominal waist is something else, like one of the bout box lines, or a proportion along the overlap. However settled in a particular instrument, this tends to leave the maker seven options for ad hoc center level reference. Thankfully, soundhole layout tends mostly to reference the 'nominal waist' level. The soundhole layouts also reference the lower bound guide for the soundholes, which is set early on the process. This tends to close match the actual lowest levels of the curves, but usually not exactly. The lower bound guide ( 'low cut' ) is set early and influences the placement of the lower eyes. However these exact placements are influenced by further factors and very frequently end up with the exact levels somewhat or significantly asymmetric. The final actual lowest curves of the soundhole are then also asymmetric and exactly placed by proportion from the soundholes. This, the 'low cut' is only a guide. Continuing. Several guide lines from the actual final corner work help box in the fair placement of the lower eyes, particularly their levels. Finally, we can discuss the setting of the radius of arc guides for the eyes. These radii are chosen ad hoc in relation to both the lower eye guides and the center levels. In earlier Cremona generations, there is a strong tendency to work these choices on the bass side, then to carry that work to the treble. There are variations in how that happens. But carrying over tends to promote more symmetry. Even in the earlier generations, they sometimes worked both sides independently. Later, the readiness to do that increase quite a bit. The 1/2 sized guide arcs from the sides then are literally 1/2 radius of the arc between the eyes on that side of the instrument. As for eye placement itself, various guides, including the ones we've mentioned, help box in the level of the lower eyes. But, the actual exact placement of this level is arcane, and it's what Strad shows in his form B, TV, and CV diagrams -- though without explanation. A guide level line is set by proportion along the center 3rd. The mechanism is same as that used to set corner levels. But the ratio choices used are generally different. In Cremona work, the level of this line is chosen ad hoc so we will end up placing our eye consistent with guides we considered earlier. In Strad's illustrations, he draws this line roughly corresponding to the turn of the purfling at the corner. This is not consistently the case in real examples. This line is part one in setting the level of the center of a lower eye. What we do is then select a diameter in oncia, like 1/2o or 1/3o, and then draw that center on the guide line. The bottom of this circle then gives the exact level of the low eye center. It's common to produce asymmetric eye levels by using the same guide line in treble and bass sides,but different drop circle diameters. However, the process is as hoc. The intent is to place the levels as our guides from the corner work already suggested. To accomplish this, makers often set different lines to drop from, as well as different drop circle diameters. A very frequent choice, giving the most frequently seen slight asymmetry of lower eye levels, is to use the same drop circle diameter, and the same ratio to set the drop line, but on one side to run that ratio across the full center 3rd, but on the other side across the inner 3rd. Once the low eye level is set, various guides can influence the horizontal placement. Including the 1/2 arc guides. In the upper eyes, three partially redundant guides influence placement: 1) the arcs from lower to upper eyes, which are with center in the area of the low eyes, but mostly to descend from one of the center levels, 2) the 1/2 arcs from the sides creating a guiding horizontal bound, 3) an explicit oncia width choices either running between the eye centers, or between or across their edges. Okay. Enough for now. Later, I'll try to show something illustrated that will be clearer and easier to follow.

Glad to see you counting the work! I agree that mostly the arcs are equal. But, I didn't find that always in my research. Occasionally the two sides are set asymmetrically. If you allow people to adjust centers , it isn't a fatal issue. However, the issue reappearsore stubbornly if you try to understand the hirizontal arc guides coming from the purfling or sides. You can see these additional guide arcs in some of the Strad diagrams In the side diagrams, there are three specifics shown regarding these arcs. Strad's examples center on the inset design line, roughly corresponding to the purf. The diameter of these equals the radius of the arcs from lower to upper eyes. And, these arcs horizontal constrain the eye centers. When you try to observe the use of these arcs in real examples, things aren't so tidy. 1) the arcs more often the arcs horizontal bound the eyes rather than giving the centers. 2) the arcs usual come from the purfling, but sometimes from the outer edge. 3) these side arcs are consistently 1/2 the radii of the arcs from lower to upper eyes, but more sensitively expose asymmetries in the layout work. There are some methods seen in setting the radius between eyes. But, these half sized side arcs make it clearer that this process is often used to the radius on one side, and then just carried over to the other. But, in some examples the sizing method is applied independently on the treble and bass sides yielding different arc sizes. Again, I'm greatly enjoying seeing you develop your software.

We have vastly fewer forms than the variety of body shapes he produced. Two more things: 1) Discussing historical practice doesn't mean you or any modern maker necessity needs to do similar. 2) You can decide to view uniquely working designs by making familiar choices and markings as you build to be 'too difficult', but another person might decide that these methods are the absolute simplest way anyone can create the specific kinds and vast range of results seen from the old masters.

Also, there's lots of evidence that these makers did work within divider and ruler markings. Diagrams from Strad show the markings pressed into the wood. His various wooden templates have divider arcs cut into them. His wooden forms have lines pressed in before inking, and cut divider arcs for the rib height guides. Classical edge work commonly shows left over scribe guide marks. They did have a tendency to show only final step geometry traces. So, there was some tendency to work very cleanly and not show all steps. Nevertheless, many traces do remain.