A constant value that when plugged into any pitch parameter, creates exactly the right pitch to test a standing wave, as that's the smallest available resolution for the oscilloscope node.
A weird math node. Basically you have a Max level (MAX) and some dynamic input (possibly velocity or pitch) and a weight. Lower weights mean lower influence on the output by the danamic, resulting in Max being outputted. Higher weights mean dyanmics have higher influence, but as the name suggests, the value will never be higher than Max.