The paper by Pablo M. Gleiser and Leon Danon explores the collaboration network of jazz musicians using a database of recordings. The network is constructed at two levels: one focusing on individual musicians (where musicians are connected if they have played in the same band) and another focusing on bands (where bands are connected if they share a musician). The analysis reveals that these constructions capture essential aspects of social interactions among jazz musicians, including correlations between recording locations, racial segregation, and community structure. The community size distribution of the musicians' network shows a surprising similarity to an e-mail-based social network studied previously. The study also examines the degree distributions, clustering, and average nearest neighbors degree, highlighting differences between the musicians and bands networks. The community structure analysis further confirms the presence of racial segregation and geographical clustering, providing insights into the collaboration dynamics in the jazz community.The paper by Pablo M. Gleiser and Leon Danon explores the collaboration network of jazz musicians using a database of recordings. The network is constructed at two levels: one focusing on individual musicians (where musicians are connected if they have played in the same band) and another focusing on bands (where bands are connected if they share a musician). The analysis reveals that these constructions capture essential aspects of social interactions among jazz musicians, including correlations between recording locations, racial segregation, and community structure. The community size distribution of the musicians' network shows a surprising similarity to an e-mail-based social network studied previously. The study also examines the degree distributions, clustering, and average nearest neighbors degree, highlighting differences between the musicians and bands networks. The community structure analysis further confirms the presence of racial segregation and geographical clustering, providing insights into the collaboration dynamics in the jazz community.