A thrilling narrative history of how one rap battle in New York transformed American culture forever. July 3, 1981, was a pivotal night for the future of America's newest art form: hip hop. In New York's Harlem World Club, the Fantastic Romantic Five and the Cold Crush Brothers competed, with an unprecedented $1,000—and their reputations—on the line in a highly anticipated rap battle. The show drew hundreds of fans to settle a question that still dominates hip hop circles: Who's the best? In Harlem World, journalist Jonathan Mael chronicles this fateful night of hip hop rivalry and shares a new look at how Harlem helped ignite a musical revolution. Since hip hop first emerged in New York in the early 1970s, artists like Theodore Livingston (DJ Grand Wizzard Theodore) and Curtis Brown (Grandmaster Caz) sought to elevate this uniquely American musical genre by pushing the limits of record-playing techniques and lyricism. The two crews they assembled put on the best shows in a world where hip hop was still a strictly live art form. Even as acts like the Sugarhill Gang and Kurtis Blow became commercially successful, New York's top two crews strove to claim the ultimate spot atop the city's hip hop scene. The battle blew the roof off Harlem World that night, and bootlegged cassette tapes of the match-up sent aftershocks around the city as more fans listened to the legendary performances. Set in the New York of the 1970s and '80s, this book shares dozens of new, exclusive interviews and a treasure trove of previously unpublished archival material to tell the story of Cold Crush and Fantastic's rivalry, documenting one of the most important stories in hip hop history. This is the first book of its kind to focus on 1979–1983 and the legendary battles at Harlem World while connecting the genre's formative years to its massive role in American society today.