The code for defining the Sine, Square, Triangle, and Sawtooth waves as well as the Oscillator and wave adder were taken from 18alantom's repository in which they are attempting to create a synthesizer with Python. Here is a link to an article the wrote documenting the process. I used other bits of 18alantom's controller file as inspiration for my main.py. Also in main.py I used the Freenove Ultimate Starter Kit for Raspberry Pi Tutorials (Chapters 7 and 8) for using a Potentiometer with the Raspberry Pi.