I would like to measure the vibrations of my drum kit to visualize it in Processing. I thought about piezo sensors, but maybe one of you has another idea. Also, it seems like there are many different Piezo sensors and I am not sure which one could be right one to measure a wide range of vibrations.
I'd use a microphone. Will have a much wider range of frequency response - seems to me piezo would be rather limited, looking at the frequency range that they output.
What are you trying to visualise? Is the the mode of skin oscillation? If so you need to measure the skin position at various points on the skin surface. That is tricky and needs a laser interferometer setup.