viola da braccio

While in London last November I visited the Leonardo da Vinci exhibit at the National Gallery and spotted a lovely painting of an angel playing a lira da braccio (credited to Napoletano). My interest was piqued.

viola da braccio - painting and instrument You see, we don’t have tons of surviving ‘real-world’ examples of instruments coming from the Renaissance (or earlier), so luthiers working in this field of early music often have to model their work on paintings and sculptures rather than technical drawings. This one looked to be a pretty good example to work from.

I lucked out and found that they did have a postcard of the painting in the gift shop. My plan to ‘translate’ this period painting into a working instrument could get underway. So how did I get from the painting on the left to the viola da braccio on the right? Read on.

In nearly all musical instrument iconography, the artist gets some details very clearly rendered and other details (perhaps those he/she was less interested in, or those harder to depict) are not. This can prove troublesome to the translating luthier. In this particular painting, it’s easy to see (due to some wonky perspective) that the instrument the painter used as a model was played as a lira: The bridge is flat and enables the musician to bow chords, rather than single or double-string melodic lines. As a result the musician need never incline the bow to one side of the instrument or the other. He/she can just keep it parallel to the plane of the strings and saw away. That would probably explain the placement of the bridge near the widest point of the lower bouts of the lira–if you never have to incline the bow, it simply doesn’t matter. The bow won’t strike the edges of the soundboard because you’re always bowing ‘flat.’ I, however, wanted to make an instrument to be played as a viola da braccio, allowing the musician to play strings singly and in pairs. The bridge, then, had to be curved and allow for the bow to angle back and forth. It’s here where things started to get complicated.

Then an even larger issue arises. How big is this instrument exactly? Given the variable sizes of musician angels, and the variety of tunings for playing the music of the spheres—and the likelihood that the composition of the painting may have been more important to the artist than accuracy of scale—I elected to make the instrument based on a string length common to the modern viola. By doing so I hoped to keep it a manageable size, and to make the finger positions familiar for modern players. With this decided, it was then time to break out the posterboard, pencils, compass, French curves, rulers and erasers to draw a basic plan.

The string length gave me the foundation for the instrument to be based on. I first moved the bridge a bit ‘up,’ that is, closer to the middle of the instrument’s box for it to work for playing melodies. With that done, I could decide how much of that distance would be neck and how much would be box. Choosing what I felt was a comfortable arrangement, I then set out to draw the box and neck in the basic shape and proportions provided by the artist. Once I was satisfied with the results (signaled to me by a feeling of ‘Hey, this is starting to look about right!’), I then traced the shape of the box onto a piece of 3cm plywood to make my internal mold. I cut out the mold with my bandsaw, refined the edges with a rasp, and cut out the center to reduce its mass. With the mold ready, I prepared the end blocks (note how this instrument disposes with the corner blocks common to the violin family) and set about bending this one long rib around the mold. (I have a video of this bending process here.)

The back of the viola is not visible in the painting, but I guessed it would likely be flat. To prepare it, I first planed a piece of wood to a suitable thickness, and then traced around the edge of the ribs with a pencil and a small bolt (helping me to keep equal distance all the way round), thus designing a lip extending slightly from the box’s periphery. With the back cut out and the lip refined, I then joined the back to the ribs. I kept the mold inside during the joining to help maintain the ‘ideal’ form it ‘expressed.’

The ribs and back complete, I set my mind again to how exactly I wanted this instrument to work. Looking again at the painting, it appears the soundboard on this lira is rather flat. I believe it was probably completely so. With no need to incline the bow when playing, the bridge can be quite short (as it doesn’t need to provide bowing ‘clearance’), and such a short bridge doesn’t put much pressure on the soundboard. So, what happens when you decide to make the bridge curved? It will have to be taller for one, which adds pressure on the soundboard. (And it would have to be really quite tall indeed to allow bowing ‘clearance’ at the bridge position shown in the painting.) And thus arises a dilemma–keep the soundboard flat but thick to keep a taller, curved bridge from pushing it in (and lose some volume and resonance), or carve the soundboard, providing a ‘dome’ structure that can bear the increased pressure of a taller bridge.

I chose to carve a dome. I felt that such a soundboard was the best choice to make in terms of clarity and volume (which early music players undoubtedly needed when playing music for large social events with people talking, eating, and drinking). Moreover, I have encountered several fiddles and violas da braccio made with flat soundboards, which if they had played well previously, simply collapsed over time. The flat soundboard, not able to provide the resistance necessary to remain flat, started to cave in, and over a period of years made the instrument unplayable. I guess this begs the questions: ‘Did early luthiers make good trade in removing and replacing flat soundboards every few years for musicians? Were musicians okay with having the most crucial part of their instrument be disposable?’ Other soundboard solutions exist, I am sure; but for this prototype, I thought it best to use a system I was sure would work.

Looking at the inside of the soundboard, you can see that I also added a bass bar for reinforcement under the pressure of heavy bass strings. It also serves to transfer vibration to either end of the sound board. Additional support and vibration transfer will be done by the soundpost (or ‘anima’). Though the soundpost is not itself pictured, you can see that the box of the viola has a bar running horizontally across its back to receive the pressure from it. Without such reinforcement, the post would slowly push through or crack open the back.

With the two halves tuned and ready, I again used the pencil and bolt to design my equidistant lip for the soundboard. And after testing how well everything fit, and giving the two parts a good cleaning, I joined them (in a gluing involving about 30 clamps like that pictured above).

I simplified the neck from the painting somewhat, choosing not to make the strings pass through the neck and into a carved pegbox ‘chamber.’ My prototype simply has the strings passing over the nut and directly to the pegs, which are inserted from the back. This certainly lightens the instrument overall, and also saves some wear and tear on the gut strings, removing an additional point of friction which would fray them. The key concerns for the neck were to make a ‘handle’ comfortable for the player, and space the pegs far enough apart that tuning wouldn’t be a misery.

Having carved the neck, it remained to join the neck squarely (both longitudinally and laterally) to the box. Unlike the modern violin, earlier instruments did not have the neck secured to the box by means of a dovetail joint. Instead, the neck was glued directly to the ribs and top block, and typically secured with a nail through the block and going into the neck. This means that necks were joined to the box before soundboards (otherwise, how would you get that nail hammered in?), but with the advent of modern glue technology, a good aliphatic glue secures the neck joint brilliantly.

The rest of the process is largely a matter of cleaning, varnishing, rubbing down, varnishing again, rubbing down again, (and so on) and finally setting up, about which I feel as though I could write a four-season television drama…

I will spare you!

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Edit: 30.05.2012 – a video of the viola being played at Tage Alter Musik