An organ pipe, when played on low to moderate pressure and allowed to reach a steady state, generates a pure harmonic tone. There is only a single audible oscil

An organ pipe, when played on low to moderate pressure and allowed to reach a steady state, generates a pure harmonic tone. There is only a single audible oscillator (either the column of air in the flue pipe, or the acoustically coupled system of the beating reed and the column of air in a reed pipe), and this oscillator is periodic, so all partials are exact integer multiple of the fundamental. This is not true of all instruments. A string oscillates both by tension along the string and by bending across the string. The bending component becomes especially important with thick strings, so a bass guitar produces noticeably inharmonic sounds. This can make the sound more complex and interesting, but it can also result in "muddy" sounding chords. A hammered string, such as used in a piano, works the same way. Pianos traditionally compensate for this by using "stretched" tuning, i.e. going up an octave is slightly more than a doubling of a frequency. This helps the harmonics of the chords line up with the slightly sharp partials of the inharmonic tone. Another way to avoid the inharmonicity is with bowed strings. Here the slip-stick motion of the bow resets the motion of the string every cycle, like hard sync in a chiptune. The bowed string in steady state is purely harmonic. Tuned percussion instruments have even more oscillators interacting. A marimba bar twists and stretches along many different axis, resulting in a complex inharmonic tone. A skilled tuner can adjust the shape of the bar to bring many of the partials close to integer ratios. The same is true of bells. See https://en.wikipedia.org/wiki/Inharmonicity https://en.wikipedia.org/wiki/Inharmonicity A pipe organ can have a noisy "chiff" at the start of the note, but whether or not this is audible depends on how the pipes are voiced. It has been considered desirable or an unacceptable fault according to the fashions of the time, so there is nothing wrong with omitting it. It is not practical to control how far the pallets are opened by partially depressing the keys. In a mechanical action organ it takes significant force to overcome the initial air pressure, which generally makes the pallet spring all the way open. Pneumatic and electric actions don't even theoretically allow partial opening. I am not aware of any organ composition which calls for partial opening. IMO a filtered chiptune wave, with good quality reverb, makes a excellent organ-like tone.