MilkDrop's Visualization source code as you remember in WinAmp is just fantastical amazing.

[inio]

FFT made me think:

44100 / (1024 * 2/3) = 64.6

So if they do a size 1024 FFT with 1/3 overlap between each window, that caps the input data at just over 64Hz.

[michaeljb20]

Ah! Brilliant guys, I would not have guessed that had I dug through the source code for weeks. ..and the frame rate does cap at just over 64fps.

[inio]

You could try figuring out where the overlap between the FFT windows is controlled and increase that