This is really cool. Imagine a map of this across a city, being able to see what different areas tend to listen to. I imagine you'd find some surprising and not-so-surprising things.
Then you'd get someone taking the trouble to correlate music and times, to capture someone moving across the city on the map.
Then you'd get profiling to potentially pick out who in particular moved across the city and the exact time of path of their movement.
While this is a nice idea on a local scale, when scaled up it has horrendous privacy implications.
Like where's the Yacht-Rock district and is Trap-House actually played near any trap houses, etc?