Extract audio frequency from instrument to find a musical note

Question

I\'m trying to develop an Android app that extracts audio frequency from an instrument. I\'m using Fast Fourier Transform method with Jtransforms. Here is what I have so far

Answer 1

For what it's worth - I believe electronic tuners for musical instruments (e.g. guitar tuners, etc.) don't do it this way. Instead of doing a FFT like you're doing, they are simply measuring the period of the waves - (i.e. the time between the zero crossings), then computing the frequency from the period.