Tuesday, June 8, 2021

My Virtual Booth at Boston Early Music Festival


This year the Boston Early Music Festival went virtual. Having been a regular exhibitor over the last twenty years I felt that I couldn't miss this one. So I registered for a Virtual Booth and it is online now. It includes a brief statement about me, detailed photos of the instruments that I have recently built, videos of my instruments played by clients and on Saturday, June 12 an Interactive Exhibition Event via Zoom breakout rooms. This offers the opportunity to visit me in my studio and discuss all things about lutes and guitars.

Go to Boston Early Music Festival and follow the links to the Exhibition.

Be sure to check out the many concerts and events taking place during the week and the week after when the Fringe Concerts begin.

I hope to see you Saturday.

Saturday, February 6, 2021

A Decacorde after René Lacôte

By last April, Covid had become a serious threat for everyone. I had had some bad experiences on my daily walks, so I was staying very close to home, becoming angry and depressed.  Then one of   my regular  clients got in touch and asked if I was interested in   building a Lacôte  decacorde, "just wondering," he said. I had   previously measured and  photographed two decacordes conserved  in  Musée de la musique,  Paris and a third in St. Cecilia's, University of Edinburgh. Immersing myself in a new challenging project sounded like the  perfect tonic.






The three instruments vary considerably in body size, neck design and aesthetic details. No single instrument appealed to me, but each had features that I wanted to model. My choices were guided by admiration for Lacôte's work, passion for the extraordinary, past experience with building models of his work and discussions with my client.

 I have included photos of these instruments at the conclusion to this post. Or if you want to read about them in detail you can  find my posts about these instruments by entering decacorde in the blog's search box.


The body design and dimensions are taken from St. Cecilia's UEDIN: 767. A technical drawing can be obtained from Friends of St. Cecilia's Hall and Museum . My finished model measures 434mm in length, 235mm across the upper bout, 167mm at the waist and 306mm across the lower bout. The rib depth at the neck is 80mm and 90mm at the tail.   Although the lengths of the three instruments are similar, the body widths of the two Paris instruments are nearly a centimeter wider. Ordinarily, I would have chosen a larger body, thinking that the additional, extended bass strings would benefit. But remembering a conversation with Raphaella Smits, who plays a small body Mirencourt built seven string (post from April 23, 2017), I decided to use the narrower Lacôte. St. Cecilia's also has a six string Lacôte with similar body dimensions that I have modeled many times so I felt confident that I was making the right decision.


While the body of one of the Paris instruments, E.986.5.1, is built with rosewood and the Edinburgh and second Paris instrument, E.1040, are built with mahogany; I chose to use bird's-eye-maple.  I have a long relationship building  instruments in bird's-eye and I have managed to keep a good stock on hand. Lacôte occasionally used  bird's-eye  and several of the theorbos that I built for this client are in bird's-eye. So that was the obvious choice.


Several surviving decacordes were built with full length fingerboards extending to the sound hole. One of the two instruments in Paris that I studied ( E.1040) is such an instrument. Others were built with fingerboards that end at the body joint and  lie on the same plane as the soundboard. Additional frets, usually to the 17th, were then inlaid into the soundboard. My client wanted a decacorde with a flush fingerboard in order to retain the playing feel of his theorbo and other lutes.  This decision offered me the opportunity to model an interesting but challenging feature that is encountered with a flush fingerboard. Lutes have their "points" projecting into the soundboard and baroque guitars often have the edge binding continuing around the perimeter of the tongue of the soundboard that projects over the joint and up the neck a few centimeters. Since the fingerboard ends at the joint between the neck and the guitar body  - what happens to the decorative edge banding? Lacôte's solution wraps it around the entire perimeter of the guitar. When I saw this for the first time I thought it was odd. 


Since the feature  has the visual flow and appeal of a continuous band I didn't want it marred by the typical joint that results where the ends of individual strips of purfling are joined.

 I chose to conceal the joint by staggering the ends of the bands and choosing a location for the joints other than on the centre line of the guitar. 

I made a series of ebony strips .8mm thick and holly strips .65mm thick that were long enough to wrap around the top half of the guitar to the point below the waist and another set that were long enough to wrap around the bottom half of the guitar. I reduced the thickness of the white bands because, when laid against black strips of equal thickness, the white ones appear thicker. I wanted them to appear equal or a little thinner.





I staggered the alignment of the strips at the starting point and included a styrene strip as a substitute for the final outer ebony band that I would apply later. Since the bands were the same length the opposite ends were also staggered. I then fitted the remaining bands around the lower bouts, being careful to snip off the finished ends to fit. I didn't get one of the joints tight enough and it became visible when I levelled the bands. See if you can spot it in the photo above. The other joints are nearby.






The neck on E.986.5.1 is a masterpiece of design, function and implementation of the guitar maker's art. Obviously, Lacôte did not think it was necessary to use a full-width piece of neck wood (mahogany) for strength and stability. Although he started with a full width board he cut a channel completely through the stock leaving an area equal to the width of a five string neck; the string disposition of Lacôte's model is 5+5. The remainder of the width serves as a support for the diapasons. The part of the neck that carries the fretted strings is shaped like his standard necks with the same roundness and thickness. The wood spline supporting the diapasons is left high and elegantly tapered to a thin point, just slightly rounded at its peak. The peg head is grafted to the neck with a long raised V-joint. We will look at the details of the peg head in a moment.



The heel construction consists of a single block of mahogany glued to the neck stock using a scarf joint. Scarf joints lengthen the gluing surface resulting, not only in a stronger joint but also, after sculpting the neck, in a graceful glue line. 


Lacôte used variations of this "scallop" design on all three instruments that I studied. This one is part of the neck of E.986.5.1.  My client wanted a wider nut spacing than early 19th century standard so I altered the peg head to suit.

The four diapasons are carried  on an extension of the fingerboard that is supported by a solid maple block. It is usually ebonized in some manner. I painted it with black shellac.   

I also tapered the end on the fingerboard extension, making it higher at the nut to give the diapasons extra clearance above the fingerboard.


While I was working on the peg head I started to think of it as sculpture. Seen from the rear, the elements of the design stand out in an harmonious complexity; the scallop contour,  the lines and arch of the v-joint, the through channel that exposes the underside of the ebony fingerboard and the channel's curved line and tapered sides. The random angle of the tuning pegs heads add an amusing twist--pun intended.

Lacôte usually spaces the fretted strings on 12 mm centers with the basses on 10mm centers. I used 11mm centers to match my client's theorbo bridge spacing.  Both spacing methods result in nearly the same total width.

His request for an equal tension of 5.0 kg or less per string resulted in the saddle compensation you see here and also for the skewed placement of the  soundboard frets.

I usually string my 19th century guitars with a major brand of light tension classical guitar strings composed of nylon trebles and silver wound basses.The tensions vary from string to string in order to partially compensate for the effect of fretting strings of various diameters. Pushing a string against the fingerboard stretches the string, raising its pitch. The guitar's saddle has to be crowned in such a way as to "compensate" for this effect. There are a number of other factors involved but I won't go into those here. The saddle compensation usually fits on a 2mm thick saddle, set slightly back on the bass side. The stopping point of the string is moved forward or back on the saddle's top surface to suit each string.  This method can result in a guitar that plays or nearly plays in tune. The use of equal tension for all strings however widens the disparity between what each string requires in compensation to the point where the saddle itself has to be moved. That is the reason for the arrangement you see here. 

For a clear and detailed explanation of guitar intonation see the article in Luthiers Mercantile;

Scale Length and Intonation for Beginners


The following photos are of the three instruments that inspired this project.

This is  E.1040. Musée de la musique. There is no label so it is attributed to the Lacôte School. The back is veneered with mahogany while the side ribs are solid mahogany. The body length is 439mm. The width measurements of the body at the upper bout, waist and lower bout are: 252mm, 180mm, 318mm.

The string disposition is 5+5 while the string lengths are 634mm for the fretted strings and 694mm for the 6th and 710mm for the 10th.

The full length fingerboard is an attractive feature for some guitarists and I might have chosen this instrument to model.

Note that the neck is extended to accommodate a zero fret, a tie-down bar and a grooved nut.

This is E. 986.5.1., also from the Musée. It contributed the design of the fine neck and peg head and much of the inspiration for my building a Lacôte decacorde model. The back and side ribs are palisander rosewood veneered on another wood.

The string disposition is 5+5. The fretted strings are 635mm while the diapasons are 649mm to 717mm. The body length is 447mm.  the  upper bout is 247mm, the waist is 182mm and the lower bout is 310mm. The depth of the body at the neck is 75.7 and 80.8 at the tail.

St. Cecilia's, University of Edinburgh, decacorde is the smallest of the three. The body length is 434mm. The upper bout is 231mm, the waist is 165mm and the lower bout 301mm. The body depth at the neck is 81mm and 90mm at the tail. 

Its neck is carved in a similar manner to E. 986.5.1 but not with the same artistry. 

St. Cecilia's decacorde has an unusually wide peg head. The only reason for broadening the peg head that I can think of is an attempt to improve the response of the 9th and 10th strings by increasing their side bearing.


All photographs by the author.

Saturday, September 12, 2020

Buchenberg Theorbo in Yew







When I reported on my last Buchenberg theorbo (June 20, 2018) there were two clients who were interested in buying it. I finally finished a second one. 

This one has several important differences. The fretted string length is 93 centimeters, rather than 89 centimeters while the diapasons remain 170 centimeters. The bowl is constructed with 29 ribs of yew rather than bird's eye maple. 











Several years ago my stock of European yew was getting low and I only had short pieces suitable for Voboam guitar backs. I found a source for western yew in British Columbia that is sold as bow staves. They are long and narrow, usually only 2 x 2 inches. Some of them are suitable for large theorbos. They are sold online with a video presentation of each stave. I started buying the most promising ones several years ago and storing them in my shop. A few months ago I felt they dry enough to start using.

I used the same construction techniques to assemble the bowl as the one I described in my post mentioned above.







 This is the string trough of the large Buchenberg theorbo No. 1570, that is conserved in the Musical instrument Museum, Brussels. See my post from August 7, 2018 for a full description of my examination of this instrument.

I modeled this design on my Buchenberg from 2018 but after complaints concerning the difficult angle of the first four strings over the nut I reverted to using a string trough with a narrow treble side cheek


I painted the string trough with a traditional oil paint. It has an egg shell finish.

The ebony line up the center of the extension is not only an aesthetic feature but also a necessary addition. The English walnut that I am using has a light curl that shows best on the quarter which is cut from the edge of the board. The board is two inches thick so it was necessary to use parallel pieces that I book matched. The ebony edge lines and the center continue to the theorbo head where they complete the simple design feature with mitered corner joins.






The face of the theorbo heads are often fitted with contrasting lines. I used walnut and ebony with broader walnut pieces.



The rear of the extension displays the same aesthetic as the front. 

A second set of ebony edge lines begin after an interruption, wrap around the head and join a cross-over line just behind the extension nut.

In my post  A Special Kaiser Theorbo (December 20, 2019) I described a technique for bending tight curves by soaking the small strips of wood in white vinegar. I tried this with ebony strips without success. 


I reverted to the proven technique of steaming the wood and then bending on a hot iron. After several more broken pieces I finally got two perfect ones. The problem lies in the poor quality of black ebony.

Bending tight curves with ebony strips is notoriously difficult. Much of the ebony that is available these days is cut from trees with irregular grain or is cut off the axis of the trunk. The strength of any wood is dependent on the wood fibers running parallel. Any deviation results in a weakness that is exposed in the wood's inability to resist fracturing when stressed.

I turn my pegs from well-aged Castelo boxwood. They are stained black with a spirit soluble stain and then lightly lacquered. I turn them without using templates. There are some inconsistencies in the shape and size. This is intentional. I believe this is one of the many features where subtle variations reflect the instrument's personality.



The core of the neck is quartered Sitka spruce. It is veneered with  strips of California Claro walnut which has a broad diagonal curl. I alternate the direction of the strips to create a random effect. The edges of he neck are veneered with ebony in order to protect against fret damage.

I always enjoy looking at the soundboard of this Buchenberg theorbo. The contour is graceful yet full of energy and the placement of the triple rose and bridge are so harmonious you can almost hear the instrument-without plucking a string.

The sound board is fine grain Swiss alpine spruce.

I often use variations of Leonardo's knots not only for its universality but also because I can cut it entirely with miniature chisels and gouges. I do my best work with these tools.

You can see all of my posts on rose carving by entering "rose carving" in Search This Blog located below the Blog Archive.

The bridge follows an often used 17th century design.

I used European plum and copied the dimensions of the large Buchenberg theorbo conserved in the MIM Brussels (see next photo).

The value of this design is that it lends itself to subtle adjustments, both when it is made and after it is glued to the lute's soundboard. I believe the design of the finials offers the same properties, effecting mass and acoustic distribution, as the cut-outs in the bridges seen on the violin family of instruments.



I would like to wrap up this post with these two views of the bowl.

This post edited 9:54 AM, September 13.

All photos taken by author.








Friday, December 20, 2019

A Special Kaiser Theorbo

After nearly two years I have finished an elaborate model of the Martin Kaiser theorbo, E.24, conserved in Musée de la musique, Paris.

Please take a look at the original Kaiser by using the MIMO portal. My story will make a lot more sense.

Enter "Martin Kaiser theorbo" in the search box and then click on the image of the lute. Be sure to click through all of the options. The images expand and can be scrolled through with the magnifying icon for a close detailed view. Keep this portal open while you read my post because I refer often to specific photos of the original lute.

The Kaiser model theorbo is not new to me. I have built over a dozen since 1997 but I never attempted to copy the detailed ivory work on the neck and extension. My clients have been young professional theorboists starting their careers so I always kept the aesthetic concept simple.

The story of this instrument is different. The client contacted me with the suggestion that I build a close copy of the Kaiser. He also wanted an instrument with low tension, low action, double stringing on the fretted strings, double tied frets and narrow spacing on the bridge and nut.

I have felt that I have drifted away from historical practice in the sense that modern players need to be heard and need to travel. I adjusted by adding a few tenths to the rib thickness or the belly and bars and adopted single stringing even though few of the many surviving historical theorbos are single strung.

I eagerly accepted the commission unaware that it would deplete my stock of black ebony, challenge  my skill and try my patience. But along the way I learned new skills and techniques and improvised on old ones. I felt I needed to do this. This is the story, in picture and words.

Where to start? I built the first few models of the theorbo using plans that I created from images of the instrument that you have seen on the museum's website and published measurements. A description of the instrument by Joël Dugot had also been published in Journal of the Lute Society of America, Volumes XVII & XVIII 1984 &1985.  Once I was able to examine the original ( March 2000) I improved the accuracy of my models.

All of my Kaiser models have been built on this mold although I have changed my technique recently. I no longer use the lines denoting the rib positions as the only means to determine the shape of each rib. Once I have fitted the edge of a new rib to the previous one I measure the distance to the edge rib of the bowl at various locations along the length of the bowl. These numbers are divided by the number of remaining ribs. I mark the results on the new rib and then plane off the excess material to the marks and then smooth them on a sanding board.

The widths of the ivory rib spacers of the original theorbo are not uniform. I recorded various widths  during my examination. I chose a median width of 2.2 mm. Visually this seems right as I compare it with photographs of the original. I also used white holly for the spacers throughout rather than ivory.

The green masking tape denotes the depth of the end cap and the two vertical lines on each side mark the two end points of the middle third of this important feature. This is a visual guide that helps me keep the ends of the ribs uniform as they pass under the end cap.

The original lute has a one piece ivory end cap with an incised black line (see the museum's photos). It is not original. I chose to use the standard early 17th century design composed of multiple pieces.

I usually build up my end caps by gluing them separately on the bowl one at a time and then cutting the finials. The work goes well but cutting the finials in place is tricky. Another technique, that I find awkward, is to construct the cap separately and glue it as one piece.

I tried a yet another method. I assembled the cap, fitting and tack gluing each piece separately on the bowl including the stepped top piece. The ends of the cap, not shown here, are left uneven. I planed the bottom edge of the cap flush with the bowl rim and then glued a piece of cotton cloth over the cap.

In the photo I have slipped a hot spatula between the bowl and the cap. The heat melts the weak glue joint and the cap comes off in one piece while also retaining its shape. I then cut the finials and glued the cap back onto the bowl using full strength glue.

The cloth support is then removed with warm water and a hot iron.


The procedure takes more time but I am happy with the result.

Before I release a new bowl from the mold  I cover it completely with clear plastic packing tape. If the bowl is too tight to the mold the tape will hold it all together while a little more force is applied. The rear end of the ribs are lightly glued to the mold but their integrity is protected by the end cap. A spatula slipped between the mold and the ribs releases the joint. I glue the front block to the front of the mold with three small drops of glue. These release when a spatula is forced into the joint.

With the plastic tape still protecting the bowl I use a curved scraper to smooth the inside of the bowl. The ribs joints are then covered with a light weight water color paper soaked in glue. The internal cap is spruce bent to shape and trimmed. A broad quarter moon shaped piece of water color paper covers the rear. This area is often the thinnest part of the bowl due to the amount of levelling that is necessary to fit the end cap and I think it needs extra protection. Only after these procedures are completed is the plastic tape removed.


I use quartered Canadian sitka spruce for the core of my necks. This is shaped and fitted to the front of the bowl. It is then covered with a hard, dense veneer in one of the many styles or designs that are represented on historical theorbos. The neck veneer of the original Kaiser is unique. It is composed of nearly 200 individual pieces of ebony and ivory arranged in chevrons.

Optical illusions created with black and white lines are popular mind-teasers. I spent a lot of time looking at photographs of the original design and decided that the white strips were slightly broader than the black even though they appear to be equal. I figured out the necessary dimensions and cut the strips of ebony and holly from larger stock.

 I laid out the design on a thin piece of plywood and using various templates to insure uniformity I glued the individual pieces of ebony and holly to the board using normal strength hot glue.

As I proceeded it became obvious that the slightest error in preparing the width of each piece would result in a misalignment of the mitred center joint.
To correct this, I constantly had to adjust the width of the individual pieces. It was a long, laborious process but the finished  result was satisfying.

Using the same technique as with the end cap I glued a single piece of cloth over the pattern. This remained in place while I planed off the plywood backing, bent the pattern to the curvature of the neck core and glued it to the neck core.

 I had second thoughts. My bending iron which is a 3 inch diameter metal pipe heated with a propane torch wasn't long enough to bend the entire pattern all at once which I thought was necessary to prevent the pattern from becoming distorted. I decided to split the pattern in half, left and right, and bend and glue separately. I also bevelled the abutting edges so the two halves would join without the possibility of a gap forming.

In the photo I am removing the cloth support after gluing the pattern to the neck core.


The result was fairly successful. I was unhappy with the alignment of several pieces so I cut them out and corrected the problem. 

I finished the neck with two white lines of holly along the edges of the chevrons and then two broader pieces of ebony that extended slightly beyond the edge of the neck core. The neck was then fitted to the bowl as shown in a previous photo.

The next step in my construction sequence was the preparation of the soundboard. The top is 6-year-old Swiss spruce. I had been working on it while I was assembling the neck veneer so it was nearly ready.

Large Italian theorbo soundboards are always impressive but I think the Kaiser soundboard is particularly harmonious due to the graceful flow of the contour, the proportions of the triple rose and the delicately thin bridge. The original Kaiser does not have a heart, but this instrument deserved one.

The Kaiser triple rose uses Leonardo's Knot as an elaborate center piece. I have always liked this design and what's better then cutting three of them?

The bridge is conserved separately from the instrument and I missed seeing it during my visit.
It is made of black ebony and is asymmetrical, larger on the bass side (13.6 mm front to back and 11 mm on the treble side) and higher on the bass side (8.5 and 7.4). The tips of the bridge are missing and whatever style they might have been can only be conjectured. The footprint of the original bridge is clearly visible and can be seen in the photographs of the instrument. To me the circular outline suggests a sunflower or rosebud. This style of finial is usually seen in paintings of 16th century lutes and survives on several surviving lutes. The top of the bridge is decorated with thirteen  6 pointed "stars" scribed into its top surface between courses. There are two scribed lines parallel to the front and back edges. There is no lip on the front edge of the bridge and the rear does not appear to be angled. I do not know if the rear face of the bridge is sculpted in any way to accommodate the string ends.

During my examination of the instrument I measured the footprint of the bridge that remained on the soundboard ( 14.2 / 11.8) and was surprised when I saw the published measurements some time later.
A very poor cleanup of the excess glue could explain this discrepancy but the lack of refinement in the construction of the bridge leads me to believe that it dates from a more recent time.

I constructed my bridge from European plum stained black and sealed with tung oil.  I created my "stars" with a small chisel, pressing it into the top of the bridge in a criss-cross fashion. I cut a string channel for the string ends to sit in.

The ebony veneered extension is tastefully decorated with triple bands of ivory/ebony/ivory and a single ivory line dividing both the face and rear veneers in half. Furthermore, on the face of the extension the triple bands are joined  in front of the ebony/ivory striped theorbo head by a crossover band with mitred corners.


On the rear the extension narrows so that all of the elements come together as nine equal bands.


The outermost bands of ivory wrap around the theorbo head and meet in a cross-over piece behind the nut.

Bending tight curves on a hot iron is a challenge. The thought occurred to me that I am substituting  a medium dense, fine grain wood for ivory and I remembered that ivory becomes pliable after soaking in white vinegar. So I cut a test strip of holly, submerged it in white vinegar (5% acetic acid by volume) for a couple of hours, and washed it off. After I allowed the strip to partially dry, it bent easily into the necessary shape with only finger pressure.

For the finished instrument I followed the same procedure but strapped the bent bands  onto the theorbo head with dressmakers elastic and allowed them to rest overnight.

I turn my pegs by hand without templates, shaping by eye and checking diameters with Vernier calipers. Many of the problems encountered with sticking pegs are caused by insufficient drying of the wood before they are turned. I use Castelo boxwood that I cut into turning squares. These are stored for at least a year. When I start a new lute I turn a set of squares to a rough shape. A while before I start applying the finish to the completed lute I turn the pegs to their near final shape. The heads and shanks are finished last and then fitted to the lute as part of the initial setup. If they are to be black, I ebonize them with a  process using quebracho extract and iron acetate. I use the process described in:
https://www.popularwoodworking.com/techniques/ebonizing_wood/  After the pegs have dried for several days I seal them with tung oil sealer.

The theorbo's bowl, neck and extension were varnished with several light coats of French polish applied in the traditional way. This was allowed to dry thoroughly and then was rubbed out with 4F Pumice stone. The soundboard received two coats of tung oil sealer, allowed to thoroughly dry and  was rubbed out by hand.

The string disposition: 8x1/6x2
The string lengths:  88.5/171 cm
Strung in gut
Information added 12/29/19
Instrument weight : 1970 grams ( fully strung)
Original instrument's weight: 1942 (without strings)
Instrument balances at the fourth fret 
All photographs by the author.