Is there really such a thing as Jewish music? And does it survive as an expressive practice of worship and identity against modernity? This book poses such questions in new and critical ways by surveying a vast diasporic landscape, taking into consideration the many ways music historically witnessed the confrontation between modern Jews and the world around them, from the waning of the Middle Ages until the Holocaust. The book examines the confluence of many styles and repertories as Jewish music: the sacred and the secular; folk and popular music; songs in which Jewish languages — Yiddish, Ladino, Hebrew — survived in isolation and songs that transformed the nations in which they lived. When Jewish music entered modernity, authenticity became an ideal supplanted by composite traditions. Klezmer music emerged in communities cohabited by Jews and Roma; Jewish cabaret resulted from the collaborations of migrant Jews and non-Jews in nineteenth-century Berlin, Budapest, and Vienna; cantors and composers experimented with new sounds. Modern Jewish music was and is varied, and this book is notable for the ways in which the borders between repertories are crossed and modernity is enriched by the shift of Jewish music from cultural peripheries to the center. Understanding the crisis of modernity — the Holocaust and its aftermath — is crucial to the challenge this book poses for understanding music in our own day.