i202 Fall 2010 School of Information, UC Berkeley

 http://mapofmetal.com/

For the uninitiated, metal music seems to fall under these general descriptors: long hair, loud and aggressive vocals, fast guitar solos, and lyrics that are probably about killing people.

But it's actually a genre of music that has been parsed and categorized to an extremely high degree of detail--something that you undoubtedly know if you are a fan, or if you have one of those friends who insists on belaboring the differences between Doom Metal and Death Metal.

Those discussions are difficult to handle sometimes because it's hard to see the forest for the trees, and to be fair, some of these distinctions are extremely subtle for a type of music that is not itself very subtle.  Plus, it's not so easy to understand the qualities that define a subcategorization of the genre without actually hearing them executed.  

The developers who created the site above solve those problems through an interesting visual interface that maps the relationship between each kind of metal, along with some other outside influences, like punk.  Each category comes with a well written explanation, and several genre-defining songs that you can listen to in their entirety.  

It would have been a little bit more helpful if they had included a zoom feature on the map, but otherwise I think it's a great example of music visualization.