The organs made by the Silbermann family are tuned with non-equal key spacing. And those are among the ones Bach played on. So if you play the same notes on a d

The organs made by the Silbermann family are tuned with non-equal key spacing. And those are among the ones Bach played on. So if you play the same notes on a digital organ, or on a keyboard, the harmonies won't work as intended. Native Instruments also offers to switch the tuning mode for their virtual/digital instruments, BTW, so that you can compensate for that in software if needed.