[stillkicking]

Cool work, but note that a 1024 point FFT isn't really sufficient to visualize music. At 44.1kHz, the lowest frequency you can resolve is 43Hz. Anything below that will be folded into your DC component. Your bass response is mostly going to be overall volume, rather than beat.

[thedjinn]

Most music is mixed not to have any useful spectral information below that frequency anyway. And if you want beat then a better thing you can do is look at the half-wave rectified difference between the sums of two FFT frames (with optional lowpass). This results in an onset graph that is the basis for a lot of real-time beat detection algorithms.