I had a cool idea about controlling a filter bank of bandpass filters, so I coded up this simple sketch. Each white pearl in this string of pearls represents a band pass filter. The horizontal position of each pearl controls the center frequency and the vertical position controls the bandwidth. You can click and drag around any of the pearls, including the red ones, which are simply anchor points for the string. The song is Lonely Rolling Star from the Katamari Damacy soundtrack.

Try it out.