The SOMA Labs ENNER, is an analog synthesizer that uses your own body as a central part of the circuitry.  The video above demonstrates the synthesizer. Here’s more from SOMA Labs:

As an instrument, ENNER is a unique analog synthesizer with the key principle being that all signals that make sound pass through and are managed by your body. Your hands become the central part of the circuitry. Touching different contact pads with different parts of your fingers and palms with different amounts of pressure, letting signals pass through your body defines the mixing, volume, timbre, feedback and other parameters of synthesis. Human skin has much more complex electric properties than we think. Our skin provides not just resistance but also some capacitive properties and even nonlinear dependence of conductivity from current, its direction and time during which the current was applied. All of this affects the sound, making you the key part of the synthesis process.

See and hear more!