When building the physical setup for my virtual organ I had to solve a few problems: Other options are available ( for a good list), but Hauptwerk does the most complete job, and there is an amazing collection of sampled organs for Hauptwerk.
I built my organ around the remarkable dedicated pipe-organ simulator software. This is the story of my virtual pipe organ.
Black Sabbath Dehumanizer Deluxe Edition. The pipe organ is very well suited to digital sampling technology, and in the last few years some very fine products have appeared that make it possible to have something like very large, beautiful pipe organs at home. I've long wanted a MIDI-based virtual organ.
