[bloomer]

This is really cool. Have you looked at all at the constant Q transform https://en.m.wikipedia.org/wiki/Constant-Q_transform which is basically a Fourier Transform with logarithmically spaces bins so that it can be aligned with traditional musical notes. Miller Puckette (Max/Pure Data) among others, has a fast algorithm for its calculation.

[avaku]

No I haven't seen this, it's very related. I guess if you wanted to use this for real time, you would still need to solve the question of window size...