Throughout the 20th century, exchanges between North America and Europe were vital to the development of musical life on both sides of the Atlantic, shifting from a postcolonial imbalance of cultural power at the opening of the century to an increasing sense of encounters between equals. There were productive exchanges of all sorts and in both directions, with ever-shifting dynamics over time. American musicians studied in Europe; European musicians visited the U.S. or were driven into exile there, orchestras and soloists crisscrossed the ocean to give concert tours; music festivals attracted...