Contemporary art music in the early part of 21st century is approaching a post acoustic world (if it is not already there). Instrumental musicians will continue to be useful for maintaining the acoustic music tradition developed in the hundreds of years of western classical music represented by past masters from Palestrina to Schoenberg, but the digital instruments and software available to composers, the variety of sounds and control of music parameters these tools make available to the composer, and the cost of live performers (often paid for by the composer) make the digital music option far more attractive, explorable and cost effective. It is also true that we now live in a digital age where the line between physical and cyber reality is blurred. Movies, television, advertising, and popular music are a constant blend of human and electronic interaction. As a culture, we are growing more comfortable and intrigued with this interaction between physical reality and cyber possibilities so that as classical composers continue to explore the design and sonic capabilities of cyber music, composing for acoustic instruments will become a relic that is representative of pre-twenty second century classical music. This post-acoustic world is already more than fifty years in the making. Beginning with Wendy Carlos's "Switched-On Bach" (1968) that featured the Moog synthesizer and began to make the general public aware of sonic possibilities beyond acoustic instruments, and in light of contemporary classical music composition techniques that move beyond the "rules" of traditional western rhythm, harmony and counterpoint, it is inevitable that exploration of sonic design and timbral possibilities are going to attract artistic and intellectually curious composers well into the future. And the future is now.