I'm looking for a program (preferably free) that can open audio files and display the results of a Fourier transform for a user-selected duration within the file. Ideally, this program would also mark the standard note frequencies on the frequency axis of the FFT plot so the user could quickly check which note a given peak might represent.
I've done a bit of googling but most of the programs I found would be overkill for this task. Also, I didn't find any that mark note frequencies on their FFT plots.
Worst case I can write a MATLAB script to do this, but I'd be surprised if a program with these capabilities didn't already exist. Any recommendations are appreciated.