This paper examines some of the core techniques used to create an artificial phonological system for Sacra Conversazione, a short opera in five acts featuring human singers, artificially synthesized voices and complementary electro-acoustic sounds. It introduces some of the most significant techniques for computer simulation and manipulation of voice used to produce materials for the piece, namely physical modeling, additive re-synthesis, PROSE and PSOLA. The author concludes with a discussion of lessons learned throughout the process of composing with such techniques.