"Researchers at the University of Rochester have digitally reproduced music in a file nearly 1,000 times smaller than a regular MP3 file."
This comes from a press release, which can be read here: http://www.rochester.edu/news/show.php?id=3136
The technology is described as something similar to MIDI format with improvements to increase accuracy of the reproduction. From the link provided you can hear two sample .wav sound files, one which had been encoded as .mp3, and the other which is recreated by use of this new experimental format.
