I'm highlighting this paragraph from the article, this is curation and beyond, great post, gets the juices flowing for all you entrepreneurs who are music fanatics!!
At its very core, the interest graph is a way to organize a social network based on people’s interests. For instance, if you’re a fan of Charlie Sheen and Lindsay Lohan, it’s clear self-destructive Hollywood stars and their lives are what you’re interested in. The interest graphs are built through various mechanisms: by following people whom you deem as experts, through your likes and shares, etc. In the middle part of the last decade, we tried to do this through tags.