Leonard Bernstein (1918–90)—the now-legendary composer and conductor—had deep roots among Eastern European Jewish immigrants in Boston. This volume of essays explores aspects of that personal and sociocultural experience as revealed through an intensive team-research seminar at Harvard University during the spring semester of 2006. Titled “Before West Side Story: Leonard Bernstein's Boston,” the course positioned Bernstein within interlocking local networks, primarily during the 1930s and early 1940s. Its aim was not to prepare a standard biographical narrative, but rather to interrogate the synergy between an individual and supportive communities, whether religious, ethnic, educational, or musical. Carol J. Oja and Kay Kaufman Shelemay designed and team-taught the seminar, guiding a group of nineteen graduate and undergraduate students in both fieldwork and archival research, and they timed it to precede “Leonard Bernstein: Boston to Broadway,” a major international festival and conference about Bernstein, which took place at Harvard in October 2006. By drawing on complementary methodologies and capitalizing on the multiple layers of activity made possible by such a large group of researchers, the students covered an extraordinary amount of turf in a short time, and they did so in innovative ways. As their work unfolded, intriguing insights emerged about the powerful, ongoing role played by Boston's Jewish immigrant community in shaping the identity and character of a man who was to become one of America's most illustrious musicians.