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The historical drawing attributed to the workshop of Enrico Ceruti that inspired the outline parameterization (a) and the geometric modeling adopted in the work (b).

The next generation of violins in a study published on Nature Scientific Reports by Politecnico di Milano

How to predict the sound produced by a tonewood block once carved into the shape of a violin plate? What is the best shape for the best sound? Artificial Intelligence offer answers to these questions.

These are the conclusions that researchers of the Musical Acoustics Lab of Politecnico di Milano presented in a study that was recently published on Nature Scientific Reports.

In the article “A Data-Driven Approach to Violinmaking” the Chilean physicist and luthier Sebastian Gonzalez (post-doc researcher) and the professional mandolin player Davide Salvi (PhD student) show how a simple and effective neural network is able to predict the vibrational behavior of violin plates. This prediction is obtained from a limited set of geometric and mechanical parameters of the plate.

The ability to predict the sound of a violin design, can truly be a game changer for violin makers, as not only will it help them do better than the “grand masters”, but it will also help them explore the potential of new designs and materials. This research allowed us to take the first steps in this direction, showing how Artificial Intelligence, physical simulation and craftsmanship can all join forces to shed light on the art of violin making.

Violins are extremely complex objects, and their geometry is defined by their outline, arching on the horizontal and vertical sections. The inspiration of this study came from a historical drawing on display at the “Museo del Violino” in Cremona. Politecnico di Milano researchers developed a model that describes the violin’s outline as the conjunction of arcs of nine circles. Thanks to this representation and an efficient model of the curvature of the plate, based on the renowned “Messiah” violin by Stradivarius, researchers were able to draw a violin plate as a function of 35 parameters.

By randomly changing such parameters, such as radii and center position of the circles, arching, thickness, mechanical characteristics of the wood, etc., they built a dataset of violins (Fig. 2), which includes shapes that are very similar to those used in violin making, but also designs that had never been seen before. Such shapes constituted the input for the neural network.

Advanced tools for the modeling of vibrations were used for characterizing the acoustic behavior of each violin in the dataset.

The next step was to understand if a simple neural network would be able to predict the acoustic behavior of a violin plate, starting from its parameters. The answer turned out to be positive, with an accuracy that came close to 98%, exceeding any expectations.

This work offers an innovative and promising tool in the hands of Cremona violin makers and, in perspective, of the international community. By using a neural network, it will enable luthiers to predict how a tonewood block will “sound” once carved into a plate. But it can also be used to design two violins with matching acoustic behavior even if built with different wood. In the future this research will allow us to select the best wood to be used for a particular violin, something that today is still based on purely aesthetic considerations.…

Politecnico di Milano is a scientific-technological university which trains engineers, architects and industrial designers.

The University has always focused on the quality and innovation of its teaching and research, developing a fruitful relationship with business and productive world by means of experimental research and technological transfer.

Research has always been linked to didactics and it is a priority commitment which has allowed Politecnico Milano to achieve high quality results at an international level as to join the university to the business world. Research constitutes a parallel path to that formed by cooperation and alliances with the industrial system.

Knowing the world in which you are going to work is a vital requirement for training students. By referring back to the needs of the industrial world and public administration, research is facilitated in following new paths and dealing with the need for constant and rapid innovation. The alliance with the industrial world, in many cases favored by Fondazione Politecnico and by consortiums to which Politecnico belong, allows the university to follow the vocation of the territories in which it operates and to be a stimulus for their development.

The challenge which is being met today projects this tradition which is strongly rooted in the territory beyond the borders of the country, in a relationship which is developing first of all at the European level with the objective of contributing to the creation of a single professional training market. Politecnico takes part in several research, sites and training projects collaborating with the most qualified European universities. Politecnico’s contribution is increasingly being extended to other countries: from North America to Southeast Asia to Eastern Europe. Today the drive to internationalization sees Politecnico Milano taking part into the European and world network of leading technical universities and it offers several courses beside many which are entirely taught in English.