People Organ

This would be an organ where each resonator and pipe is replaced by a person and each keying mechanism is replaced by a more human form of communication like direct touch, eye contact or vocal prompting.

It's sort of baked in the form of the monster-o-phone on the Muppet show where they guy hits monsters of varying sizes on the head with mallets and they "ouch" out tunes.

But instead of having the monsters facing away from the mallet weilder, and towards the camera, the "people" (in this case) should be facing the "organist-conductor" so that the organist-conductor can learn to play the people with eye contact, gesticulations and vocal prompting. Conventional signals could be worked out like hand gestures up and down for pitch, facial expression for volume, etc. It would be the ultimate test in conducting - conducting a choir without any score. Maybe this is common practice at vocal conservatories. I bet it would be a great way to practice group communication. Another thing would be to let each choir member improvise a little according to what they hear around them. Another option would be to incorporate touch as part of the control mechanism -- so that the choir members would crowd around the conductor so that he could manipulate them by touch maybe stretching their arms out with pitch lines drawn on the arm so that the conductor could play a keyboard made of arms -- although this would be closer to the Muppet version. The touch version might make it easier for the conductor to become a physical virtuoso.

The possibilites for two people playing eachother like this would probably be pretty interesting as well. Two people touch eachother with anti-mirror symetry, say each reaching out a right hand to touch the other's left elbow and singing unison tones. Then each could move their hand on the other's body as well as changing their own voice in response to the other's hand movements on their body. Conventions could be worked out in real time. Limits could be drawn or dispensed or negotiated in real time. I guess this could also get out of control pretty quickly. Maybe that's why you don't see more of it going on on street corners.

An add-on to this last bit would be a theraputic argument technique. Two people could learn to argue constructively by learning to manipulate eachother's vocal chords through hand to body touch-signals. So if one person wanted to say, "you never listen to me," they would have to (having first worked out the conventions with the other person) manipulate the other person body such that the second person would vocalize the phrase, "you never listen to me." The hand-signal conventions and the technique and area of the body for manipulation/contact would be the hardest part to figure out. But the figuring out would itself be theraputic. Probably hand to stomach would work, allowing mutual contact and range of motion. The vocal tract could be mapped onto the stomach -- consanants up and down and vowels side to side -- and presure could be volume, or something like that. The specifics would be better worked out in practice. But the point would be to allow each participant to think out what they were, "saying" and also to get a feel for the other person's point of "view".