The twenty-first century has already seen some aesthetically exciting sacred architectural spaces. Much liturgical music, however, is centuries old. With regard to performing old music, philosophers such as Steven Davies, etc., have debated the aesthetic merits of striving for authenticity of performance. If authenticity is a valid performance aesthetic principle, as I contend it is, the following paradox arises: Some contemporary sacred spaces are the sites of moving, aesthetically valid performances of sacred music. But how is it possible to have aesthetically valid authentic performances of sacred music in twenty-first century sacred spaces?... The question of authenticity in this unique musical genre focuses on performance space, liturgical function, musical instruments, performer/listener interaction, and cultural conditions. ...Using architectural examples constructed in the twenty-first century, this thesis will propose a set of aesthetic criteria for achieving an authentic setting for sacred music from all periods. / by Daniel Copher. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.