Squaresynth is a module of a costumized simple synthesizer based on quad oscillator on my earlier post here. It uses the same chip, 4093 and modified it as a touch/moist sensor. I developed Squaresynth for workshop purpose, to invite the participants learning the basic electronics through introductions of electronics logis such as oscillator, introduction in reading schematics, and also introduction on electronic components. The demo showed how it sound above. Documentation, schematic, PCB design bellow.