The sleeve notes of my CD "Yikhes: Frühe Klezmer-Aufnahmen von 1907-1939" state:

Klezmer music in the form known today is less than 200 years old, but its roots date back to the Middle Ages. This traditional instrumental music of Yiddish-speaking Jews of Eastern Europe was played at weddings and other celebrations and came to the New World with the waves of emigration of 1881-1924.