Accurately sampling a pipe organ is no simple matter, due to the dynamic and harmonic range of the instrument.
With large instruments, mixture ranks often go beyond 8 KHz, especially the mutations, e.g., nazard or quadragesima, the latter which sounds at G9 (~12 KHz) when C4 (middle-C) is played. As mixture ranks typically are flue pipes tuned in just intonation, they generate very pure difference and sum frequencies, the latter going into the ultrasonic range. The lowest difference frequency is usually the fundamental of the note actually being played, which results in a harmonically-rich sound that has challenged recording engineers ever since the days of Edison cylinders.
At the other end of the audio spectrum, there’s this.
What does your wife have to say about all these acoustic aspirations of yours?