This is a pure data patch and the score for swëlst - a piece for organ and live electronics. You can download everything you will need to perform this piece here. To run the pure data patch just open the "swelst.pd" file and follow the instructions there. The patch requires the convolve~ external, which can be installed directly in pure data (go to "help" -> "find externals online").
The piece is dedicated to Matthias Geuting and the Walcker-Organ in Essen Werden.