A map of “favorite artists by state” went viral in the fall of last year. However, data was misinterpreted by researchers. The map didn't show the favorite musician of every state, but instead showed an artist who was more listened to in comparison to other states. More information was gathered again from the same site, and a map of the most-played artist in each state was created. This survey was collected through music streaming data available through The Echo Nest.
The later survey shows that the East Coast listens to predominately rap, especially Jay-Z.
It seems like rap has taken over the music scene in the USA.