Klezmer (Yiddish: קלעזמער or כּלי־זמר) is an instrumental musical tradition of the Ashkenazi Jews of Central and Eastern Europe. The essential elements of the tradition include dance tunes, ritual melodies, and virtuosic improvisations played for listening; these would have been played at weddings and other social functions. The musical genre incorporated elements of many other musical genres including Ottoman (especially Greek and Romanian) music, Baroque music, German and Slavic folk dances, and religious Jewish music. As the music arrived in the United States, it lost some of its traditional ritual elements and adopted elements of American big band and popular music. Among the European-born klezmers who popularized the genre in the United States in the 1910s and 1920s were Dave Tarras and Naftule Brandwein; they were followed by American-born musicians such as Max Epstein, Sid Beckerman and Ray Musiker.

After the destruction of Jewish life in Eastern Europe during the Holocaust, and a general fall in the popularity of klezmer music in the United States, the music began to be popularized again in the late 1970s in the so-called Klezmer Revival. During the 1980s and onwards, musicians experimented with traditional and experimental forms of the genre, releasing fusion albums combining the genre with jazz, punk, and other styles.