Architetture per il “recitar cantando”: geometria e progetto nel Teatro Petrarca di Arezzo

From the middle of the eighteenth century the growing passion for the "recitar cantando" of a larger public in Italy, fosters an extraordinary proliferation of architectures for opera, which are carried out not only in big cities but also in many smaller towns. The kind of theatre called all’italiana is so structured in a building type characterized by some precise typological invariants , which are, however, declined from time to time according to different shapes and sizes.The basic tool for the design control is Geometry , which is expressed on the one hand in testing of multiple regulatory tracks to determine the best icnografic and orthografic framework, foreshadowing a first taxonomy of functional and formal requirements, on the other hand in application of sophisticated perspective models in set design, aimed at the high emotional involvement of the viewer in the scene space. However the geometrical procedures used by theatres designers, even where it is possible to reconstruct the implementation process through documentary direct sources, are not always explicit. In particular, the understanding of a specific geometric and constructive configuration can be achieved only by the architectural survey in the methods and with the techniques of scientific inquiry, in a close comparison with the past cultures of the measurement and representation. In this line of research it is proposed a study of the Petrarca’s Theatre of Arezzo, an Italian-style theatre, built in 1833 on the design of the Florentine architect, Vittorio Bellini. The chosen plan framework is an horseshoe shape considered at the time the most suitable for ensuring in every part of the hall the best conditions of visibility and acoustics. The theatre is equipped with 85 boxes, putting in four tiers, which together with the hall seats can contain up to 600 spectators. The architectural survey conducted preliminarly to restoration works (completed by a few months) and then deepened and validated during construction activities, also with procedures of laser-scanner acquisition, made it possible to trace back a particular design process regulated by strict geometric matrices, set on the ancient measurement unit, the Florentine arm. Together with the analysis of the exceptional design drawings of Bellini and the substantial nineteenth documentation for procurement and construction, still preserved in the archives, it offers an unprecedented reading and interpretation of the geometric genesis of architectural configuration of the theatre.