Acoustical aspects of the development of Greek theaters in the 4th century B.C.E.

In ancient Greece, the 4th century B.C.E. was a time of rapid development in arts, culture, science, politics, and theater architecture. The first part of this article describes the origin and use of the Greek theater building and its connection to the Dionysus cult and festivals with musical and drama competitions. Next, scientific context is discussed as a background regarding the highly skilled architects who designed these theaters. The 4th century B.C.E. is characterized by the blooming of the sciences, especially mathematics, strongly stimulated by Plato's Academy near Athens. The architecture of the theater changed within this century. While earlier theaters had mostly rectilinear seat-rows, symmetry and a stricter geometry started to characterize theater design. In this study, six theaters were selected for acoustical analysis: three of them with rectilinear shapes, and three of the well-known semicircular form. Acoustical analyses show that the archaeologically demonstrated shift in theater design from a simple rectilinear shape to the historically canonical semicircular shape was a way to increase theater capacity and at the same time improve the acoustics. Acoustical analyses reveal some of the design principles that can explain the excellent acoustics of these theaters and the applied knowledge of their designers.