Considering Black metal bands' family tree according to Wikipedia, this is the candy floss that is produced using Gephi:

With excellent instruction from Tony Hirst's post on mapping related musical genres, the graph takes as its starting point bands that are in the Black metal genre. Next, it relates all other genres that are listed in the information box on each band's Wikipedia page. As an example, this is Burzum's information box:

This data is queried using Gephi's Semantic Web Import plugin and the following query:

  prefix gephi:
  ?genreA gephi:label ?genreAname .
  ?genreB gephi:label ?genreBname .
  ?genreA  ?genreB .
  ?genreB  ?genreA .
?band  .
?band  "group_or_band"@en.
?band  ?genreA.
?band  ?genreB.
?genreA rdfs:label ?genreAname.
?genreB rdfs:label ?genreBname.
FILTER(?genreA != ?genreB && langMatches(lang(?genreAname), "en")  
&& langMatches(lang(?genreBname), "en"))


Stylistic origins

Having created a Black metal-centric universe where the biggest node (according to PageRank) is obvisouly black metal as we asked for this in the above query, curiosity naturally turns to the 'genealogy' of Black metal. Where does Black metal fit in with the extended (family) history of music genres?

To answer this question we'll use the stylistic origins that are listed in the information box for each genre to create a new network. As an example, Black metal's stylistic origins are listed in its information box on Wikipedia.

(And what does the snappy acronym 'NWOBHM' mean? Well, think: Lemmy.)

With further help from Tony Hirst's post on the history of programming languages we arrive at the following query to extract the appropriated graph:

prefix gephi:
prefix foaf: 
  ?a gephi:label ?an .
  ?b gephi:label ?bn .
  ?a  ?b
?a a .
?b a .
?a  ?b.
?a foaf:name ?an.
?b foaf:name ?bn.


This creates a directed graph that links all music genres with their stylistic origins. Applying PageRank to the network and running Force Atlas 2 for a while produces the following universe of music genres:

Unsurprisingly, Spiritual, Blues and Gospel are prominent genres in the (western) music universe.

The bottom part of the universe is red after applying the colour to Black metal and genres two degrees away from Black metal ('Neighbours of neighbours' in Gephi). Punk rock is clearly a significant influence in this corner of the music genre universe.

Filtering on Black metal and allowing three degree of stylistic influence before and after, Punk rock, Psychedelic rock and Hardcore punk come into view in the red cluster:

Removing one degree of separation, Black metal emerges (in the middle of the cluster) as a derivative of Punk rock, via Hardcore punk:

Reducing the view to Black metal and one degree of separation, we see that Black metal is a product of Hardcore punk, Thrash metal and Speed metal (at least according to Wikipedia):

The imaginatively named subgenres of Black metal also come into view: Drone metal, Melodic death metal(!), National socialist black metal, Symphonic black metal, Unblack metal(?) and, wait for it...

Viking metal.

Source: DBpedia; Graphics by: geirmund