Using ideas from Nicolas Colin’s book Handmade Electronic Music, I built an original feedback circuit using a CMOS Hex Schmitt Trigger Integrated Circuit (CD40106) and a 9v battery. I have a total of three oscillators. They are all in series, where the output of the first is the input of the second, and so on. The last oscillator has a blinking LED before its output which is taped to a photoresistor in the first oscillator, therefore modifying its signal. The second and third oscillators also have potentiometers and photoresistors which I am modifying by hand and with a bike light (but the photoresistor in the first oscillator remains isolated to the LED).