Generations of European classical music composers made their livelihoods at the behest of courtly patrons, developing their craft (and feeding their families) as they turned out countless scores for ballrooms, theaters, and chapels. Patronage played a role in American music, too—but here, the siren song of Hollywood arguably played a bigger role in how music developed in America. Studios offered handsomely paid work, while keeping the sounds of orchestral instruments in the ears of moviegoers who might never visit a concert hall. Composers like Bernard Hermann, Elmer Bernstein, and John Williams became household names, crafting timeless scores that would enter the concert-music canon. And few can match the extraordinary success achieved by the charismatic composer, pianist, and conductor Leonard Bernstein, who fused urban swagger with jazz and Latin dance music to create one of the 20th century’s most beloved works: West Side Story, a perennial hit on stage and screen.