It stands in the middle of the room, surrounded by woodworking machines, plans and the cases of its “relatives” : the new prototype for a concert hammered dulcimer. An older model of this type of instrument is slightly further towards the back. Looking at the new development, the first striking aspect is its elegant shape. A comparison reveals the reason for this: compared to the old instrument, the soundboard and belly of the resonance body are slightly arched on the new dulcimer. The angles of the base area are also different. The instrument weighs 20 kilograms, the front edge being 100 centimetres long and the rear edge 58 centimetres. The distance between the two sides is 65 centimetres.

Even the bare figures may reveal something to an expert. But how on earth does a half-naked instrument, that is to say one that is only half strung, come to be standing now in Werner Alder’s hammered dulcimer workshop in Herisau? It all began with an idea by Fredi Zuberbühler, a member of the “Anderscht” music ensemble (1), for a further development of the Appenzell concert hammered dulcimer with an expanded Werner-Alder tuning. He drew up plans with the aim of increasing the instrument’s register and improving its scaling, i.e. the instrument’s dimensions. The intention of the latter was to cause the pitch levels to be determined mainly by the string lengths and less by the string thickness and tension.

To ETH via a high-tech carpenter

Discussions with the instrument makers Urs Stieger from Berneck and Werner Alder from Herisau revealed (2) that the concert dulcimer that had been sketched out imposes completely new demands on its design. For example, it was realised that for stability reasons the resonance body would have to be arched. But how was the difficult shape to be achieved? Zuberbühler asked the Bach carpentry company in Heiden(3), which is well known for its computer-assisted production. They pointed out to him that the designtoproduction group of the ETH Chair for CAAD might be able to help in implementing the plans (4).

At ETH, Zuberbühler met a sympathetic listener, the passionate guitarist Christoph Schindler. Together with his ETH colleague Fabian Scheurer, the architect developed three-dimensional plans that can be used directly to control the Bach Company’s CNC milling machine. Schindler explains that “We developed the geometric design for the hammered dulcimer. This means that the soundboards are each part of a pair of imaginary cones with a radius of 10 and 12 metres respectively and whose cone apexes are offset.” The ETH scientists also optimised the thickness and arrangement of the wooden components in such a way that they withstand the resulting tensile loading of up to 1.7 tons.

A new world of sound

In the workshop, Alder and Zuberbühler explain other special features of the new hammered dulcimer, which the instrument builder said would later probably cost about 15,000 Swiss francs.

A new concert hammered dulcimer, built with the assistance of ETH expertise, nears completion in Werner Alder’s workshop in Herisau (Photos: Christoph Schindler) large

Inspecting their new development, not yet fully strung: Werner Alder and Fredi Zuberbühler. large

The instrument, which has been enlarged by one octave upwards and by a sixth downwards compared to the classical Appenzell hammered dulcimer, contains a novel bracing in the resonator box. Alternatively, the string length can be varied on both sides of the central bridge. Listening to the specialists, it becomes clear they are still playing around with details quite apart from the wrest pins.

However, they have already achieved their real goal: the dulcimer has a larger compass, its tuning is more stable, it is elegant and it has a volume hitherto unknown for this instrument. When Zuberbühler makes the hammers dance, first on the new development and shortly afterwards on the older Appenzell concert dulcimer, a new world of sound opens up, principally in the lower registers.

Audible progress

That’s why the musician and the dulcimer maker are already looking forward to the new instrument’s première performance. Fredi Zuberbühler wants to hold this at ETH Zurich, since without their help he would not have been able to make the project a reality. It will also be a special occasion for Christoph Schindler: “The project represents a fruitful merging of tradition and progress.” In the autumn the result of a scientific development will then for once be audible as well as visible.