The National Ballet of Canada's "A Disembodied Voice" features a score by John Oswald for the recorded voice of Glenn Gould, robot piano, ghost pianist, and orchestra. The piece premiered in the programme entitled "Inspired by Gould" which ran from November 20th to the 27th at the Hummingbird Centre in Toronto.
The half hour composition is in 10 sections, each of which takes a different angle on Gould's musical preoccupations. Several technological innovations were utilized by a team under the direction of Oswald which researched and created materials during most of 1999.
A major bit of sonic archeology was the dissecting of Glenn Gould's 1981 recording of the Aria of the Goldberg Variations. First the piano was filtered out of the recording as much as possible, leaving Gould's inadvertent vocalizations as a more prominent element. Christopher Butterfield in Victoria made a phonetic and music notation transcription of this vocal line. Where there was difficulty ascertaining a sound the team studied a video tape of the Gould recording session to see what Glenn's mouth was doing.
Eventually Christopher's brother, opera tenor Benjamin Butterfield, was recorded reproducing a version of Christopher's transcription, with his own revisions. Christopher was also recorded, and several takes of his version were layered in combination with Benjamin's solo version to produce a chorus of Glenns near the end of the Aria. To this Oswald added a klangfarbenmelodien-like arrangement (this is a technique where a melody line is passed from instrument to instrument, changing its timbral colour over time) for live orchestra, which gradually added clues as to the source.
For the performances the monophonic voice of Gould "walked" via routing through several hidden speakers from behind a canopied area on stage to the orchestra pit where it was joined by the chorus.
Meanwhile in Toronto, Ernest Cholakis, who is best-known for designing the groove templates found in various sequencers, worked on making a very precise MIDI transcription of Gould's piano performance of the Aria. This transcription was designed to be played back on a Yamaha Disklavier very similar to the piano Gould played for the original recording. The result was a reproduction of the piece, minus Gould's voice, which is much more realistic than any hi fi system could ever recreate using the original recording. Audiences remarked about the ghostly presence of performances of this, in a sense, live acoustic piano recreation.
These two Aria derivations were the bookends of a composition which featured abstractions and plunderphonic derivations of Gould's own music and some of his favorite pieces, including works by Richard Wagner and Petula Clark. Bach and Mozart clash in one section, and the Disklavier was a featured soloist throughout.