Project coordination and contacts
Email address: domenico (at) astraproject (dot) org
Francesco De Mattia
Conservatory of Music of Parma - Italy
Email address: francesco.demattia (at) conservatorio (dot) pr (dot) it
(Responsible for Development Activities) University of Salerno - Italy
Email address: salvatore (at) astraproject (dot) org
Giuseppe La Rocca
(Responsible for GRID deployment) INFN Catania - Italy
Email address: giuseppe (dot) larocca (at) ct (dot) infn (dot) it
(Modelling/Testing) Conservatory of Music of Salerno - Italy
Email address: mariapaola (at) astraproject (dot) org
Archaeological data, such us fragments from excavations, written description pictures, etc, are quite ofter used to retrieve information about how things was working in the past.
In the ASTRA project, archaeological information are used by a quite large community of scientists and musicians working on the reconstruction of sound or timbre of ancient instruments (not existing anymore).
The physical modelling sound synthesis technique aims in fact to use a set of equations and algorithms that describe the physical materials used in the ancient instruments to generate physical source of sound. In other words, the basic idea is to recreate a model of the musical instrument and produce the sound by simulating its behaviour as a mechanical system.
For example, to model the sound of a drum, there would be a formula for how striking the drumhead injects energy into a two dimensional membrane. Thereafter the properties of the membrane (mass density, stiffness, etc.), its coupling with the resonance of the cylindrical body of the drum, and the conditions at its boundaries (a rigid termination to the drum's body) would describe its movement over time and thus its generation of sound.
Similar stages to be modelled can be found in instruments such as a violin, though the energy excitation in this case is provided by the slip-stick behaviour of the bow against the string, the width of the bow, the resonance and damping behaviour of the strings, the transfer of string vibrations through the bridge, and finally, the resonance of the soundboard in response to those vibrations.
Although physical modelling was not a new concept in acoustics and synthesis, having been implemented using finite difference approximations of the wave equation by Hiller and Ruiz in 1971, it was not until the development of the Karplus-Strong algorithm, the subsequent refinement and generalization of the algorithm into the extremely efficient digital waveguide synthesis by Julius O. Smith III and others, and the increase in DSP power in the late 1980s that commercial implementations became feasible.
Physical modelling is a really computing intensive technique since the complex models of the musical instruments are solved by integrating numerical coupled differential equations. To correctly reproduce a sound lasting for 30 seconds more than 4 hours of CPU would be required. The ASTRA application package, would produce one or more sounds corresponding to different configurations of the instrument (i.e., different notes).
Relation with other projects
The ASTRA package is currently being deployed on the EUMEDGRID infrastructure and first tests have been successfully carried out in July 2007 on the INFN GILDA (Grid Infn Laboratory for Dissemination Activities) infrastructure.
Moreover, in the context of future development, the possible exploitation of the DILIGENT framework will be investigated. DILIGENT has established a standards-based test-bed which integrates state-of-the-art Digital Library and Grid technologies to support a wide range of research and industrial applications. With DILIGENT, members of Virtual Organisations can create on-demand, transient Digital Libraries based on shared computing, storage, content, and application resources.
A Knowledge Management Environment based on DILIGENT guarantees secure, coordinated, dynamic, and cost-effective collaboration and sharing of knowledge. DILIGENT can potentially facilitate the exploitation of the EUMEDGRID infrastructure to support the adoption of the ASTRA application from the targeted user communities through a personalised and secured portal offering high level services and based on the sharing of resources (grid, content and applications). DILIGENT services could be successfully used to provide a transparent, effective access to the distributed sound files generated in the several countries and prepare customized reports (for different user communities like conservatories, museums, universities, archaeologists, etc.).
+ Il progetto ASTRA: la ricostruzione di strumenti musicali antichi e le moderne tecnologie di calcolo, GARR07 Network Humanitatis, September 29, Rome, Italy, Programme
+ Scientific Data Sonification and the ASTRA project for ancient instruments reconstruction within EGEE, EGEE07 Conference, October 1st, Budapest, Hungary, Agenda
+ WP4 Status and future plans, EUMEDGRID Techinal Board, September 4th, Damascus, Syria, Conference Home Page