There's some pretty interesting math that went into creating this map, so definitely check it out in its original context at musicmachinery.com. Using days analysis, the author is trying to identify an artist that is popular in one state, that doesn't get as much love elsewhere.
A few states that I had to call out:
New Hampshire: Awesome, they get the Grateful Dead, but since they're pretty popular all over so I guess I was surprised that they even made the list
Vermont: Congratulations, you guys got the Phish. Totally makes sense.
Illinois: My home state. Sufjan? Really? I guess the Illinois album had a strong pull and lingering effect
Massachusetts: The Dark Horse for Neil Young. Way to go.
Arizona: LOL @ Linkin Park
