Sets Y to sine and X to cosine of degrees, tracing a circle as degrees increase from 0 to 360. At regular time intervals, program plays notes with pitches proportional to X position and Y position on the circle. Instrument is randomly changed with each note (goofy). 2nd pen matches the Y coordinate as it moves forward. A sine wave results.
2nd pen moves forward the distance of the circle circumference traveled, 2 x pi when radius = 1. Notice motion of Y position slows down at ends and is fastest near 0, as in a pendulum and spring motion (a sine function). You can head that pattern in the notes. Two notes are played simulataneously, one proportional to the X and the other to the Y position of the circling point. While there is beauty to the circle and sine wave, the musical choices here are admittedly silly. You can make out a general melody that is counterposed according to the X and Y position on circle. I rounded off the notes to make them sound more pleasing, avoiding dissonance. You might want to remove that rounding off function to better hear what the X and Y positions on the circle sound like. Accompanies my simpler demo of sine wave resulting from circling motion (uses no trig): https://scratch.mit.edu/projects/500868935/
