As Charles Garnier prepared the design for the Paris Opera House in 1861, the lack of acoustical design information and the contradictory nature of the information that he found forced him to leave the acoustic quality to chance and hope for the best. With few exceptions, this was the condition of architectural acoustics at the beginning of the 20th century. In 1900, with the pioneering work of Wallace Clement Sabine, the dark mysteries of “good acoustics” began to be illuminated. In his efforts to remedy the poor acoustics in the Fogg Art Museum Lecture Hall (1895–1973) at Harvard University, Entries A–F 19 Sabine began experiments that revealed the relationship among the architectural materials of a space, the physical volume of the space, and the time that sound would persist in the space after a source was stopped (the reverberation time). Predicting the reverberation time of a room provided the first scientific foundation for reliable acoustic design in architecture. This method i...