I can't recall how I came across Hauptwerk, but it was/is written by an Englishman in Birmingham, though his company is now part of a small American specialising in digital sampling. I've had a copy since the beta for v1 over ten years ago (it's now at v4). It's used around the world both for practice organs, and as a way of archiving the sound of historic organs. I have sample sets of Salisbury and Hereford Cathedral organs, a couple of baroque French organs, several Czech and Hungarian organs (including one which has samples of before and after a recent restoration); also several harpsichords, a carillon, and a steam calliope!
Some reasons a special sampler is required are:
(1) Polyphony - for a large organ recorded with a long acoustic and played fast, polyphony levels of around 10,000 may easily be required. You can't achieve this streaming off disk - all the samples need to be in memory. To play the largest available sample sets requires at least 48GB of memory and eight or twelve cores! My home machine has 32GB and a four-core Xeon which handles polyphony of about 5,000.
(2) Wind effects - the program models the effect that playing one pipe has on the wind supply to another... I'll leave it at that. Also the tonal effects of swell shutters and tremulants are accurately modelled.
(3) Retuning - the samples are resampled in real time (remember that polyphony?) to enable different temperaments and pitches to be applied to the original samples.
Some reasons a special sampler is required are:
(1) Polyphony - for a large organ recorded with a long acoustic and played fast, polyphony levels of around 10,000 may easily be required. You can't achieve this streaming off disk - all the samples need to be in memory. To play the largest available sample sets requires at least 48GB of memory and eight or twelve cores! My home machine has 32GB and a four-core Xeon which handles polyphony of about 5,000.
(2) Wind effects - the program models the effect that playing one pipe has on the wind supply to another... I'll leave it at that. Also the tonal effects of swell shutters and tremulants are accurately modelled.
(3) Retuning - the samples are resampled in real time (remember that polyphony?) to enable different temperaments and pitches to be applied to the original samples.
