Abstract: Certain effects of pipe organ wind regulators and conductors, as well as certain effects of acoustic coupling of pipes within pipe organs are emulated in an electronic musical instrument. Digital signal processing is used to model the behavior of a pipe organ wind regulating and distributing system as a damped oscillator to which an input disturbance signal is applied. The disturbance signal is derived from the combined on or off state of notes associated with voice generators responsive to the model output. The output is further processed and used to control the absolute pitch of the voice generators. Response controllers regulate the response of the generators individually. By varying the response characteristic of each voice, the relative pitches of the voices diverge as more notes are played, achieving a psychoacoustic effect similar to the detuning produced by wind pressure variations and acoustic coupling among speaking pipes of a pipe organ.