  Using a database of jazz recordings we study the collaboration network of
jazz musicians. We define the network at two different levels. First we study
the collaboration network between individuals, where two musicians are
connected if they have played in the same band. Then we consider the
collaboration between bands, where two bands are connected if they have a
musician in common. The community structure analysis reveals that these
constructions capture essential ingredients of the social interactions between
jazz musicians. We observe correlations between recording locations, racial
segregation and the community structure. A quantitative analysis of the
community size distribution reveals a surprising similarity with an e-mail
based social network recently studied.
