A sixty year-old concert bootleg, made on a broken and twisted old magnetic wire earned a bunch of audio engineers and a mathematician a Grammy last night for their skills in recovering destroyed music. The audio recording on the wire was so distorted, and the wire broken so many times, that the team had to invent whole new techniques to process the music back to listenable quality. The result: the only live recording of old time folk-singer Woody Guthrie.
The recording was made in 1949 by a student at a concert in Newark, N.J. When it was eventually found and played recently, the ancient magnetic wire had stretched and twisted and was so frail it broke often. It took 36 hours of work to just get the audio safely off the wire and into a computer, and even then the tracks were peppered with holes, slowed-down sound and missing high-frequencies.
By finding rhythmic sounds buried in the recording, and using mathematician Dr. Kevin Short’s signal processing algorithms, the team carefully pieced together the tracks, interpolating holes and correcting for distortions and speed-shifts. The resulting album, The Live Wire, was nominated for the Best Historical Album category in the Grammys. You can listen to tracks showing just how nifty the processing was via the Science News link. [Science news and University of New Hampshire]
