"The breakthrough that zenph has achieved is to extract the sounds from audio recordings and convert them into a high resolution version of MIDI... To do this they had to tackle the problem of polyphonic transcription - distinguishing several notes played simultaneously as seperate entities... While researchers have been trying to achieve this for years, previous attempt have managed to identify at best 80 to 90 percent of notes correctly, with about 10 percent missing or wrong. "We have only begun to see excellent results in the last few weeks, the results are note perfect" says John Walker, Before founding zenoph in 2002 John Walker was the leading developer of VoIP.
The enginners then playback a stereo version of the music, one channel has the original recording, and the other has there midi derived audio version "if there even a few miliseconds out, the ear can immediately hear there something wrong"
This technique could be used to clean up old recordings by deleting unwanted parts of the midi info etc...."
