Afterwards, we used the user ratings to compute the similarity between the artists. Essentially, for each pair of artists, we counted the number of users that rated both artists highly to determine the similarity. This operation gave us the artist-artist similarity graph. In the image below, we show the clustered adjacency matrix of the graph. The blocks you see in the middle of the picture are similar groups of artists. (In fact, this is how we got the color for each artist in the final picture.)
