A sample of the Myspace social network is examined. Using methods from complex network theory, we show empirically that the structure of the Myspace artist network is related to the concept of musical genre. A modified assortativity coefficient calculation shows that artists preferentially form network connections with other artists of the same genre. We also show there is a clear trend relating the geodesic distance between artists and genre label associations - that is artists with the same genre associations tend to be closer in the network. These findings motivate the use of on-line social networks as data resources for musicology and music information retrieval.