BACKGROUNDWhat is taught in different violin making schools and has reached to our times comes from a few treaties, documents, measurements made in the nineteenth century in the best instruments and some molds made by those who were the biggest Cremonese violin makers of the XVI-XVIII centuries. Thanks to the new technology and the efforts of luthiers interested in science and scientists fully involved in violin making, today many of the "secrets" of these instruments has emerged, with respect to its tonal quality. Still, there are some mysteries to be discovered in order to build with considerable control high quality instruments. One of the least investigated topics is the direct correlation between the properties of materials, the perceived tonal quality and performance characteristics. While the sound radiation is the result of vibration of the structure this can be used directly (?) The perfect coupling properties of the top and bottom woods has not yet been investigated although this is one of the crucial questions that violin makers ask themeselves. The excellent sound of some instruments depends on the first three or four vibration modes of the complete box, in wich the bottom, with top and garlands, fully conditions the formation of these modes.Jesus Alonso Moral made a first investigation in 1984, in Sweden, as part of his PhD, combining three different tops with three different ribs and three different backs -soft, normal and stiff- to try to understand the interaction between them related to the tonal quality of the instrument. Today precision in measurements is greater. The theories about the behavior of the violin are more accurate and a we have a more rigorous perceptual evaluation protocol based on the psychology of perception. Andrea Ortona conducted a similar experiment along with 20 students in Cremona but it was no possible to control correctly the parameters.OBJECTIVESThe key objective is double: on the one hand the control of the violin maker on the construction parameters, so that the demands of performers and listeners on the tonal quality of the instruments are satisfied, and on the other hand the implementation in the Study Plan (Curriculum) of a methodology to widen the capabilities of the students and also increase the prestige of the school, increasing in this way the employability of the students attending the studies.PARTICIPANTSThe members have been selected by their experience in each of the different phases of the project: Roberto Jardón Rico for his experience in handling CNC, George Stoppani for his experience in the creation of the revolutionary modal analysis method and subsequent interpretation. Andrea Ortona for his experience in managing a similar educational project in Cremona school, and finally Claudia Fritz for her experience in the assessment of the perceptual quality.DESCRIPTION OF THE ACTIVITIESFive Violins will be built, using woods with carefully selected properties. First, three violins with identical tops and different backs and later two violins with different tops on three identical backs will be made. Both tops and backs will be built by CNC to a pre-selected form to accurately control this variable. Then they will be tuned and measured in different stages: thicknesses, frequencies and masses, in the Violin Making school of Bilbao by the students, with supervision and collaboration of the project members. Finally a double-blind perceptual quality test will be performed with the collaboration of professional musicians and specialized audience. Once this phase is finished the intellectual products and their dissemination will be created.PLANNED IMPACTIf the results are conclusive and they respond to the working hypothesis, the impact on the violin maker community will be very important regarding to the control and quality level of the products that will be obtained.Also, the skills acquired by the students and by future generations will increase their employability and the quality of their products. Moreover, the Study Plan (Curriculum) will be adapted to the new teaching methods.LONG TERM BENEFITS-Increase of the skills in the (Curriculum) Study Plan.-Better training of the students.-More prestige for the school with a consequent increase of the students employability.-More Control of materials and processes, and better quality products made by violin makers.-Satisfaction of the music sector.