The UMBEL people (Fred and Mike) just released a new interlinkage diagram. This time, it doesn't represent the different links amongst datasets made available within the Linking Open Data project, but rather a map of the links amongst vocabularies used on the data web.

Vocabulary interlinkage

The Music Ontology sits right between FOAF, FRBR and the Event ontology (although I would have added the Timeline ontology as well). There is also the Programmes Ontology, at the bottom (which is also interlinked with the Event ontology, btw).

This diagram really helps to see how the current web ontology landscape is structured, and I hope we can keep use it to keep track of the evolution of web ontologies, a bit like what has been done for the available datasets and interlinks.