NOTES ON THE EARLY MUSIC SHOP ALTO REBEC KIT
by Paul Butler

The Early Music Shop in England has produced a new rebec kit. I have acquired an alto (tuned to lower three violin strings), and here offer my commentary and history of construction. You can click on any picture to get the higher resolution version of it.

THE KIT
Plan
Overall the plan looks good. Would prefer crescent shaped sound holes rather than flamed, and do not think that soundpost is necessary (not to mention really hard for somebody who is not practiced in it to set given the rounded body shape), especially given the arched soundboard. Not totally sure that the fingerboard has to extend over the soundboard, but that is fine. Gives the instrument a little more flexibility. Definitely need to hollow out the neck, and I'd even suggest hollowing the fingerboard from behind as well to lighten overall.

Body

General note: Wood (beech, I think) is good- nice looking, hard enough for decent sound but soft enough to work without dulling tools or having difficult grain (like curly maple). The body almost could be left unaltered if somebody lacked the tools/ability to do further carving on the inside bowl, and could just be thinned with files/sandpaper from the outside to achieve a usable instrument (though more work would be required to acquire a fine instrument). Need to pre-hollow neck (I understand this would normally be done). Taper of peg-holes was fine, and should be done at factory as peg-reamers are not a standard tool most people have lying around, and are difficult to acquire at the local hardware store (though I have found that file tangs will work in a pinch).
Special issues with this piece: these are points for the particular body I received, not with the body design/execution in general. There were a couple of problems with the individual piece.
There were three issues with the peghead. The first was inconsequential. The angle of of the sides of the peghead were machined purely vertically, rather than perpendicular to its face as in the plans. This created a "back-swept" look to the peghead, with the bottom of the peghead jutting forward of the top. Personally I think it looks good that way and decided to leave it - but it does differ from the plans provided. The peghead was also cut assymmetrically, and needed to be evened out by about 1/4"-3/8" on one side. Again, not a big issue, and pretty simply corrected. The third was a little more major, as there are two gouges out of the top face of the peghead, each about 1/8" to 3/16" deep. They would require a fairly substantial removal of wood to erase, which would be both annoying and potentially structurally problematic. They look like clamp or guide jig marks. I was able to soften, but it does scar the appearance some.

The body itself had a number of clamp or pin holes in it which were easy to remove and did not pose a problem, save for one. What looked like two small chips in the base of the bowl on the exterier (I thought they were clamp marks) turned out to be a 1/16" hole drilled through the wood of the body (it was about 2.5" long - marked by red arrows in picture). It passed within less than 1/32" of the pre-carved bowl, and had I tried (as I initially did) to erase it from the outside by carving the wood down to its bottom level, I would have cut through the bowl of the instrument. As it was, I ended up having to patch the area and leave something of a scar, which is rather distressing and might compromise the sound of the final instrument a bit. I'm hoping my patch job will prove sufficient. There were a couple of chips out of the sides of the top, but I don't think any will compromise the joint with the soundboard as none go entirely through the wood. Otherwise the wood carved easily and smoothly.

Soundboard

General note: Wood (Swiss pine) again is good, has a nice tap-tone, and again could be used without carving, just thinning it out on the outside with files/sandpaper to generate a decent instrument. Though again, proper thinning with chisels (as I did) generates a better final result. Guess it depends how much work you want to put into the kit. I personally would say that leaving the sound-hole shape and configuration up to the builder might actually be the way to go - means a little less work by the kit preparer, and gives more creative control of the instrument over the to kit maker. It is the one variable feature of the instrument, and might provide a chance for more "personal expression". Just a thought.
Specific issues with this piece: Nice piece, grain lined up well. One chip out of the side a little deep, but not too deep to fix if carving. Otherwise fine.

Fingerboard

General note: Here the wood (Swiss pine again) is not acceptible. It needs to be either solid hardwood or hardwood veneered softwood. I personally would suggest hollowing it out from underneath to lighten the instrument somewhat.
Specific issues with this piece: the wood here was literally cut from the same piece of pine as the soundboard (I could actually line up the grain). While it was cut well to dimension and machined well, the wood is too soft. My nail casually would scar it, which I think makes it inappropriate for a fingerboard. I personally substituted American white holly wood for this (I carved a new fingerboard, see below), as it is: a good hardwood, easy to carve (nice tight grain), would aesthetically look interesting (white fingerboard and tailpiece seemed pretty to me, and nicely different), and I happened to have a piece on hand. Lacewood, sycamore, walnut, pear, or even more beach would work fine I think (or lime, willow, etc.- whatever is locally available). I personally wouldn't recommend maple as it is a pain to work with (tends to dull tools quickly), or the tropical hardwoods as too expensive and not terribly representative of a medieval instrument, which would most likely have been made out of whatever wood was locally available (as opposed to Renaissance decorative bits). I personally don't like veneers, but that also might be a solution.


Tailpiece
General note: again, I think here the wood (Swiss pine) needs to be a hardwood - whatever you end up using for the fingerboard. The shape, design and mounting are otherwise perfectly fine. I ended up subbing a piece of white holly to match the fingerboard. Because of the harder wood, it could be carved thinner and finer than the pine plans called for, though the weight ended up about the same.

Fittings
Bassbar - good piece, curve required only a little bit of work to fit exactly, so machined well in the first place. Might thin it a tad, but that can be left to individual maker. Endnut - the ivorite works fine. The specific piece I had was chipped on one corner too deeply to use, so I substituted some mammoth ivory I had floating around. Though the fingerboard hardwood might also work here as well. Pegs - good to have them pre-tapered and shaped. Again, I had one that was chipped on one corner, and I ended up reshaping them from squared tops to spade tops (my personal preference anyway) to fix. Wood (boxwood?)is nice. Strings - gut is preferable, and the gut supplied is good. They seem to be good quality. Length was fine. Tailgut was also included in a deep brown. Bridge - fine. Good wood, cut sufficiently.

Case

A hardcase come with the instrument. It is quite nice, fits the instrument quite well, and has a nice pocket for extra strings, supplies, etc. The bow holder is a little awkward to work with. The closings are combination locked, but hold well. Overall quite nice.

Bow

The kit also includes a small, simple bow that is basically matched to the instrument. Unfortunately this particular one was strung with nylon rather than horsehair, but that particular error will be resolved. Otherwise it is sufficient, and decently enough balanced to work with the instrument. No rosin was included in the kit, but that is easily acquired elsewhere.

CONSTRUCTING THE INSTRUMENT

1. Started out by thinning the body from within the bowl with chisels. The body needs to come down to about 1/16"-1/8" thick. Chiselled out the bowl, hollowed out the neck, leaving the neck walls thicker to keep the neck more sturdy. Thinned the walls until the walls were able to be slightly flexed.


2. The bowl was then sanded down with paper to smooth out the chisel marks and even out any irregularities in thickness. The top edges are undercut a bit to allow for a larger joining surface with the soundboard and to give some space to round off the joint.


3. Next, evened out the shape of the peghead, which was slightly assymmetrical. Done with straight chisel and files.


4a. Set aside the body for the moment, and turned to the soundboard. Drew a midline on the underside. Then marked the point where the bridge would be with a cross line, and the ends of the soundholes.


4b. The soundholes were positioned around the bridge crossline, and drawn in using a card template to make sure they are symmetrical.


5. Drilled out holes to start off the soundhole. Using a coping saw, cut a rough shape to get started. The final shape was cut using an Xacto blade (Stanley knife) and small files.


6. Next, fit the soundboard to the body to determine the overhang, and marked that. Marked the line where the soundboard ended abutting the fingerboard and cut that to length with a coping saw, straightened with a file. Marked the edges of the fully hollowed soundboard. (NOTE: you may notice that the soundholes don't match their original positions. Originally I had marked the top and bottom points of the flame shaped soundholes from the original plans. I realized, however, that the crescent shaped soundholes should be centered around the bridge, so I repositioned them appropriately before cutting them out -I didn't bother to erase the old lines, however).


7. Using chisels, hollowed and thinned the soundboard to shape, carefully working around the soundholes. Thinned evenly all across, with a slight thickening at the edges to account for rounding off when joined to the body. The top at the point where it meets the fingerboard also has to be angled down and thinned.


8. Sand down the soundboard inside to smooth it out and even out any irregularities in thickness. Remark the center line, and where the bassbar will be placed.


9. Fit the bassbar to the soundboard. Note where it does and doesn't touch. Mark where it touches and cut or file (I prefer filing - more fine tuned control) down where it touches until more of it touches, and repeat this process until 100% of the bar is in contact with the curve.


10. Glue down the bassbar. I "clamped" with carefully placed handweights. The bassbar should be under a very slight amount of tension.



11. Carve down the tailpiece to thin it out and hollow out with chisels. Mark carefully where to drill holes, and drill holes through. Holes should be just large enough for the string to get through without snagging. Sand down to smooth out. (the different colors here are the original pine tailpiece provided, and the white holly tailpiece I replaced it with)


12. Draw centerline on fingerboard and mark line where it will meet the soundboard. (again, the different colors here are the original pine fingerboard and the white holly piece I replaced it with - same goes for below)


13. Line up the fingerboard and soundboard on the body to position, and note height at joint.


14. Carve out the hollowing at the soundboard end of the fingerboard close to the edges and smooth down (chisels and sandpaper). Make a notch where it meets with the soundboard. Cut with straight saw a small line as deep as the end of the soundboard is high. Then with straight chisels, chip out the notch to create small ledge to fit against the soundboard.


15. Refit against the soundboard and make any necessary adjustments.



16. Next, hollow out the solid block of the fingerboard. Draw out margins to allow clean gluing surface to the body, and then chisel out. Leave the fingerboard top surface at least 1/8" thick. This is done both to lighten the piece and add a hair more volume to the interior space.


17. Double check all fittings of soundboard/fingerboard. Make sure the fingerboard and soundboard butt against each other cleanly and in a straight line. It is much easier to adjust the pieces before they are glued into place.


18. Glue the soundboard into place. Clamp this however you can. Strong rubber bands, hand weights, zip ties, etc. Just be careful not to damage the soft edge of the pine soundboard doing so. Please note that the bottom of the body is rounded, and should be braced before putting weights on in this position.


19. Sand down the top of the soundboard and clean up edges with body.


20. Glue down the fingerboard. Remember the underside area where it overhangs the soundboard will need to be sanded to final finish before doing this, as it will be very difficult to get into that space after it is glued down. Used hand weights again to do this, though regular clamps will also work - just remember to cushion the clamping on the underside of the neck especially.


21. Clean up edges with body on the fingerboard, and do the final sanding pass of the whole instrument. Also at this time the tail knob to a clean rounded shape. You can see the clean grain in the body in the side view here.


22. Finish the body however you are finishing it. Sealant and lacquers can be used on the body and soundboard, but only use oil on the fingerboard. Don't get lacquer into the pegholes, though they should be sealed. Be careful not to seal over the soundholes. I used violin fingerboard oil on the fingerboard, and International Violin Company Violin Oil Varnish (3 coats).


23. While the body is drying in its stages of varnish, sand and oil the tailpiece in similar fashion to the fingerboard. Make sure the strings can fit through the string holes, and that the tail gut can fit through its holes before oiling. Roughly shape the endnut to the width and curve of the end of the fingerboard and mark the notches where the strings will fall. Reshape the pegs to taste (I prefer the spade shape, so I reworked them into that appearance).


24. Position the bridge. Shape the feet (sharp knife or files) of the bridge to completely match the curve of the finished soundboard. Note that the bridge, when view from the side, is perfectly perpendicular to the soundboard facing the back and sloped slightly in the front. Shape the hole of the bridge to desire (I used a simple peaked arch). Cut the notches in the bridge with either a sharp knife or a small v-file. They should be just deep enough to not allow the string to slip, but not so deep that the string rests entirely in them. Remember the bass strings are larger diameter than the treble.


25. Position the endnut in place, plane or file so that it butts up against the fingerboard cleanly. File down the endnut to desired height, and cut notches in the nut. Remember the deeper strings need more clearance of the fingerboard than the higher strings, as they tend to vibrate more vigorously. The nut channels also tend to work better as square in cross-section rather than V in cross-section. The nut isn't glued into place, but is held in place by tension of the strings.


26. Tie the tailgut onto the tailpiece. It sometime helps to run it under some hot water to soften it enough to tie the knots. Be careful, though, as it will "set" into that shape when it does dry. The tail loop should be snug enough that the tailpiece is held right over the endnut of the body.


30. Put on the first string to test the setup (see note below if you are installing a soundpost). The best string to use is the middle string. Tie a slip knot on the end attached to the tailpiece, and wrap around the peg. Do not cut the excess string yet. Stretch the strings gently up toward pitch and check the string clearance of the fingerboard (the "action"). The string should be around 1/16-1/8 of an inch above the fingerboard (the image above shows it much too high, as it probably will be when you first put it in on). If the clearance is good at the nut, but too high toward the bridge, cut down the string notch on the bridge and refit. If the clearance is overall too high, start by lowering the nut end by deeping the string notch and re-sitting. Continue this process until the action is as desired. When you are satisfied with the action, carve down the bridge so that the curve of the bridge is just above the notch; likewise with the endnut.


31. Add the other two strings, and then slowly bring the strings up to actual pitch. The gut does stretch more than metal strings, and will take about a day or two to settle into pitch. Don't panic over the creaking sounds of the wood and gut - they are normal. Be careful to make sure that the bridge doesn't tilt forward as you tighten the strings (it will tend to do so) - gently nudge it back vertical.

32. Rosin up the bow and play away!

THE FINAL INSTRUMENT



The instrument as it finally appears, from top, side and angled front views.

Settings the sound of the instrument: The rebec as an instrument has two sound problems. The first and primary one is volume. The body is very small, the soundboard even smaller, and this tends to make a very quiet instrument. My original soprano rebec was built rather solidly (something I'd hoped to remedy with this instrument), and has a fairly quiet sound. The tone is resonant and nasal as it should be, but the overall volume is very little. Outside of a small, quiet chamber, it would not be heard in performance. The second problem is that the instrument tends to have a thin, not very resonant sound. I had inadvertantly solved this problem in my original instrument by having a very wide soundboard. The arched soundboard on this instrument should also solve that problem.

I strung up the instrument as originally intended as an alto, using Gda' (the lower three strings of the violin). The sound was okay - a bit thin and not very loud. Given the lightness of the instrument compared to my other rebec, I was expecting more volume from it, and was particularly disappointed with the lower end, which had no resonance at all. The a-string, however, was fairly powerful and clearly resonant, and suggested that the heart-rage of the instrument was closer to a soprano than an alto.

I decided to tinker to see if I could get better sound out of the instrument. First I lightened the bridge significantly by thinning it a bit, and curving in the sides considerably more than the original design called for. I also increased the height of the underarch a little. This actually did improve the sound a bit more, and now the D-string was beginning to have a fairly decent sound. The G-String however did not significantly improve, and still sounded rather thin and tinny compared to the A.

As an experiment, I restrung the instrument as a soprano, using da'e' (upper three strings of the violin) using a spare gut e-string from my treble vielle. The e-string turned out quite powerful - as much so as the a-string, and actually generated a decent volume. Just that way it would have been a fine instrument, and generated a nice tone. It however was still not as loud as I wanted, so I decided to see if a soundpost would affect the sound at all.


The image is a little misleading, as it should be "adjusting the soundpost" rather than inserting it. It should be inserted with the bridge down and no tension on the strings, preferably before the strings have been brought up to pitch. In any event, I carved a spruce soundpost to a 6mm diameter (about the same as a violin soundpost) and inserted it, initially cheating it toward the treble side. It actually did boost the volume measureably, though not as much on the d-string. I then adjusted the positioning a little toward the bass end (what I actually thought to take a picture of above) and that pulled the d-string up nicely.

The end result is a soprano instrument that is on par with resonance and volume of my tenor vielle, which I was quite pleased with. Playing it discovered a couple of things. First, I'll probably re-do the nut as the string spacing at the end of the fingerboard is very wide. It's perfectly fine for this instrument, and not a problem structurely or accoustically, but since I tend to switch back and forth between my various strings in performance, the spacing is far enough apart to be distracting moving between instruments. A violinist would probably find it distressingly distant. It also makes doing double stops with a single finger difficult (I have fairly large, broad fingers so it wasn't a problem, but a friend of mine trying it out couldn't get one fingertip to engage two strings). Next I discovered that one should bow about 1/4-3/8 inch from the bridge to achieve the best sound - a little closer than I bow on the vielles. Bowing further down worked fine, but cut the volume down a bit. Bowing closer to the bridge excited it more, and gave a richer sound. I was also surprised at the finger positioning. The string sounding length is almost identical to my treble vielle, but the finger spacing seemed farther apart, closer to a viola than a violin, using a more standard reference. It may simply be an illusion of the wide-spaced strings. It was a little odd at first, but quickly adapted to and I haven't had a problem with it.

Recordings to follow, compared to violin and treble vielle.

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