I've never used 'pitch' and I've never plucked spokes. I'd guess this would change depending on spoke gauge, pattern, and hub/rim dimensions. Why bother with it other than to check consistency? Am I right in thinking you can't use the same note if you're building wheels w/ different thickness spokes? At the shop level I have to use processes that both accurate and repeatable. That's why we use torque wrenches and tension gauges. The 3 senior mechanics at the shop I'm at have nearly 90 years of combined experience. We don't 'think' we're right at 5nm or 110kgf we know.