Page - (000166) - in Knowledge and Networks

159 Fig. 8.4 Evolution of centrality measures: degree and betweenness (Design by author) groups are cohesive: Elite-1, Ivy League, and Shooting Star-1. Elite-1 and Ivy League clearly occupy a central role vis-à-vis other trajectory types, suggesting that those two groups played a coordinating role in this field. The Swing Era: 1935–1945 The consolidation of swing as a popular style came in the late 1930s. The popularity of its musicians enabled them to bridge racial chasms, as exemplified by Goodman’s partnership with Teddy Wilson. A close connection with a monopolistic recording industry also helped structure a centralized organizational field. As Peterson and Anand (2002) observe, in the mid-1940s the phonographic field in the United States migrated from a normative to a competitive model. Several explanations exist for this shift. The first relates to the domain of law and regulation. The founding of Broadcast Music, Inc (BMI) in 1942 broke the American Society of Composers and Publishers’ (ASCAP) monopoly on music royalty distribution agreements and per- mitted the shift from the New York Tin Pan Alley formula to the introduction of new styles (Hobsbawm, 1989; Peterson & Anand, 2002). The number of recording ses- sions fell dramatically in 1942 (see Fig. 8.5), which had the effect of loosening the leadership of established swing musicians. An inspection of the geographic distribution of the sessions reveals that New York and Los Angeles still accounted for the majority in the mid-1940s. However, there was a clear shift from New York to Los Angeles due to the usage of jazz in movies (Fig. 8.3). In Europe, jazz declined in London, but expanded in pre-World-War-II 8 Trajectory Types Across Network Positions: Jazz Evolution from 1930 to 1969