Variations on Vater unser im Himmelreich is a electroacoustic remix of Felix Mendelssohn's Organ Sonata No. 6. In the 2001 original source recording, Patrick Wedd played on the Karl Wilhem organ of Christ Church Cathedral in Montreal, Canada.
To put it succinctly, the original recording is pre-treated with granular synthesis and then transformed and spatialized in Ambisonic B-Format in realtime using stochastic controllers.
Audio file preparation was done with sound editor TwistedWave, granular synthesizer Audio Ease Thonk and sound editor/mixer Steinberg Nuendo. The Audio Units plug-ins used for live performance and responsible for random routing, processing and spatialization were built with SonicBirth. The live performance is done in Plogue Bidule where the multichannel file playback and processing all come together.
A more detailed explanation is available here: http://www.radio.uqam.ca/ambisonic/music.html
Calibration method: The file has seven channels: WXYUVPQ. Use the first three (WXY) with a 1st order decoder. Use the first five (WXYUV) with a 2nd order decoder. Use all channels with a 3rd order decoder.