Our research group at the International Audio Laboratories Erlangen is working on some topics in music perception. We ran several experiments to find out: What is the number of instruments in polyphonic music humans can estimate correctly? To compare our internal results with a broader user base, we published a new web-based listening experiment at WICE : Web Instrument Count Experiment We would be very thankful for your participation. The experiment takes ~10 minutes to finish. Any feedback or questions about the experiment are very welcome!