http://www.linusakesson.net/music/reverberations/

About the technology

It struck me that, at least in theory, organ pipes should generate quite primitive sound waves. If so, how come a church organ doesn’t sound like a chip tune, which is also built up from simple waveforms? Well, actually it will, if you remove the church. And if you connect a Commodore 64 home computer to a loudspeaker in a large hall, it will sound like an organ.

So the music on this album is not performed on a pipe organ. Instead, what you hear is the sound of one or two SID chips (controlled by a Commodore 64), enhanced by a convolution reverb to simulate church acoustics.

Vía: opaco.org