We were actually thinking about doing several things to make it more clear what the controls on the left do
- Highlighting the part of the drawing arm corresponding to the control that the mouse is hovering over.
- Introducing something in the controls that spins in sync with the frequency the control is... controlling.
- Printing the frequencies as text, like "-f*2", "f*0" in the controls.
...but in the end we were way too slow. Most of the final version was written during the last day.
Our hope was that it might somehow make intuitive sense somehow without requiring users to know about the math.