Figure 6. Hierarchical clustering of violin shape.

Clustering based on averaged harmonic coefficients by prolific luthier (>45 violins). Four main clusters, named by prominent luthiers they contain, are indicated by color. As discussed in the text, know copyists of Antonio Stradivari cluster with the Stradivari cluster, and often members of the same family cluster together. Members of family houses that cluster together are indicated. Blue, Maggini cluster; red, Stradivari cluster; purple, Amati cluster; green, Stainer cluster.