Much disputed! The engineers and piano tuner/designers of "TuneLab", "Verituner," "Sanderson Accutuner" etc etc--all high end piano-tuning programs tell you, basically, NOT to spend money on a measurement microphone. Why? Because piano-tuning software is based, essentially, on measuring "partials" generated by piano strings; and those partials can be measured very accurately by the cheapest mic on the market. Spending even, say, 100 bucks on the cheapest of measurement mics (with ostensibly flat frequency response and low distortion) is just a complete waste of money. A 5 buck mic will serve just as well. Seems counter-intuitive, but these folks seem to be in agreement; and they are the engineers behind the product. What gives? Is this true? And if so, why?