I first ran into the need for this a few years ago working on a sound design for a production of Don't Hug Me. Not having the requisite experience in midi equipment, I did not make the attempt to do this, but it seems like it would work, and I'd like to toss this out to see how it would be done, and what equipment would be necessary. The sequence ran like this. Many times during the performance, the actors would enter/exit the set. The subtext of the story is that it is extremely cold outside, and every time the door is opened, the sound of the howling winter wind can be heard. We were using SFX as the cueing software, and I was using 2 cue lists, one for the primary effects, and a separate list for the wind. This wind cue list kept the wind effect looping continuously and silent. The first cue would raise the cue level when the door was opened, the second cue would drop it by about 80%, and then automatically fade to silent for 10 seconds (keeping the audio file looping meant that every time the door was opened, the wind would be different). To time it out, the SM had to call the cue and actor entrance/exit together. Given that the door opening was the trigger for the first cue, and the door closing was the second, it seems like MIDI could take care of the cue firing. I envisioned some kind of door sensor (maybe a burglar alarm mag sensor or such) connected to some kind of MIDI signal generator, which could be connected to the computer and assigned through SFX to fire the appropriate cues. So what I need to know is: 1. Is this an approach that would work, crude though it may be? 2. Exactly what equipment (aside from the computer with SFX or other cueing software and a MIDI input for it) would I need to pull this off reliably?