Investigations on the acoustic response of two heritage buildings designed by Galli Bibiena and disappeared from history in the 18th century: The Nancy and Tajo opera theatres

The development of melodrama during the 16th and 17th centuries brought the architects to the elaboration of a different variety of geometry for the main halls of opera theatres. Unfortunately, nowadays there are only a few theatres designed and built during the Baroque period since most of them are completely destroyed. The architectural investigations carried out on two case studies belonging to the Galli Bibiena family have been taken over for a complete acoustic assessment. The digital models related to the Nancy and Tajo opera theatres were built from the outcomes and discoveries on the historical resources consisting of drawings, sketches and general documents. The digital models were used for the acoustic simulations carried out on the main acoustic parameters that evaluate the quality of speech and music inside these two case studies. The simulated results indicate that the acoustic response in the Nancy and Tajo opera theatres is very similar to each other, although the small difference between the two theatres is mainly in function of the volume size rather than other architectural features. Overall, the simulated values are found within or closer to the optimal range set by the criteria, which support the assumption of speech and musical performances given in the royal palaces, the place in which they were erected.