In the 2006 edition of my newsletter The Scroll, I wrote about an experimental 15” viola model I was developing. My Opus 573 viola, dated 2006, was the result, and while it achieved the goals I was working toward it did not sell, so I set it aside. It continues to show well and be a very successful small viola with a dark, rich sound. Recently I have made two more violas on that form. Demand continues to grow for small violas with that richness. Aging violists seem more motivated than ever to down-size, while violinists need to become more versatile by adding viola to their résume. More and more people want a small viola that sounds like a great viola.
In late 2005, I abandoned my reluctance to build anything smaller than the 15-5/8” model that continues to work well for me. My work on smaller violin models made me 
think I could deal with the plate stiffness issues inherent in smaller outlines, and the continuing success of a 17.25” asymmetric viola model I developed years ago gave a direction for the basic design. I did not want to move too far away from the basic principals of proportion, symmetry and balance essential to good instrument design.
The major design innovation was to shift the acoustic centerline of the instrument (neck and string placement) to the treble side at the neck, and to the bass side at the tailpiece. The effect I hoped for was easy left hand access to the upper positions and the instrument as a whole brought closer to the player’s body. The string length is as short as normal strings will allow and the neck-to-body proportion is close to normal.
The characteristic dark viola sound is largely the product of the air volume inside the viola. Volume can be maintained in a short instrument by increasing rib height or increasing width, but there comes a point where lack of proportion in these elements leads to a reduction in efficiency and balance in tone. More is not better if it is not working efficiently as part of the whole system. I still want to see how much each of these elements can be compromised and still maintain an overall balance. These violas are noticeably asymmetric, but overall they maintain classic design principles and details.
My prototype of this experimental model, Opus 573, was built in March of 2006 and was ready to play that fall. It is now on loan to a promising young player in New Jersey. My Opus 885 is made with red sycamore and Opus 905 is made of the more conventional maple.
About these instruments:
Viola #573 15” Cut-Away
The viola bears the label “Douglas C. Cox, Brattleboro, Vermont, 2006, #573” and is branded and initialed on the inside. It is built on an original, asymmetric model of well-aged North American grown wood. The back is cut on the quarter from two pieces of Vermont maple with medium width flames descending toward the bass side. The ribs and neck are of similar maple to that of the back. The table is of two pieces of Engelmann spruce from British Columbia of even, medium-narrow growth. The varnish is of a red-brown color over a golden ground and is shaded and imitated. The fittings are of boxwood with ebony trim. The principal dimensions are:
Body Length: 385 mm
Upper Bout: 200 mm
Middle Bout: 141 mm
Lower Bout: 246 mm
Rib Height: 36-38 mm
String Length: 355 mm
Viola #885 15” Cut-Away
The viola bears the label “Douglas C. Cox, Brattleboro, Vermont, 2015, #885” and is branded and initialed on the inside. It is built on an original, asymmetric model of well-aged North American grown wood. The back is cut on the partial slab from one piece of red sycamore from Pennsylvania. There is a knot between the C-bouts on the bass side, and knot-like figures on the bass side of the upper bout. The ribs are of red sycamore similar to that of the back. The neck and scroll are of plain Vermont maple. The table is of two pieces spruce of mostly wide growth. The varnish is of a red-brown color over a golden ground and is shaded and imitated. The fingerboard is of hop hornbeam or ironwood. The fittings are of boxwood with cream-colored trim. The principal dimensions are:
Body Length: 386 mm
Upper Bout: 199 mm
Middle Bout: 140 mm
Lower Bout: 245 mm
Rib Height: 36-38 mm
String Length: 357 mm