I started Googling “map of music” because I was interested in seeing if there was one, and if there wasn’t one I was going to try to create one on my own with ArcGIS. I couldn’t find the type of map I was looking for, but I found this neat map: Map Of Metal.
The map is not a world map, but rather a original creation by the site maker that creates land masses based on certain types of metal and rock music. Each land mass is a genre, or a few related genres, and each genre will dish out several applicable bands for that genre. It’s quite interesting, you should check it out! There is sound as soon as you enter the site, so make sure your volume is at an appropriate level.