While Jewish music is extremely varied and clear boundaries can be difficult to define, there are three main categories. Ashkenazi includes European styles such as klezmer. Sephardic is primarily the music of Jews from the Mediterranean including Spain, Portugal, North Africa, Greece and Turkey. Mizrahi is the music of Jewish communities that were based for thousands of years in Arabic countries. There is also Israeli popular music, which incorporates all of these styles as well as Western pop and folk music.

Derived from the Hebrew word for "German", Ashkenazi referred originally to Jews who settled in Europe's Rhineland valley and northern France in the 9th century, but it now includes most Jews of Northern and Eastern European descent. The Yiddish language is a hybrid of German, Hebrew and various Eastern European languages and was the common language among Ashkenazi Jews for many years, although its prevalence has diminished due to assimilation. Still, Yiddish remains an important part of musical expression.

The best-known type of Ashkenazi music is klezmer, a word that is derived from the Hebrew words kley (instrument) and zemer (song). Klezmer's rich history extends back hundreds of years, when it developed among Jewish communities in Eastern Europe (Poland, Russia, Romania, Bulgaria, the Balkans, etc.). Itinerant klezmer musicians would wander from town to town, enlivening weddings, bar mitzvahs and local celebrations with their fast-paced dance tunes. Subtle echoes of Jewish music's ancient Middle Eastern past can be heard in klezmer, but it is the influences of Eastern European folk music and gypsy music that are most evident. Originally string bands, the violin led early klezmer ensembles, although the clarinet also became an important solo instrument.

Faced with economic hardships, ceaseless discrimination and abuse, European Jews began emigrating en masse to the United States in the late 19th century. They brought their music with them, and in the early part of the 20th century klezmer music thrived in New York City and other Jewish enclaves. The music soon began incorporating local influences such as swing, foxtrot and Dixieland.

After a long decline in popularity, klezmer has experienced a revival as a new generation of Jewish musicians seek to re-discover their cultural heritage. The music has been given a new vitality as groups like The Klezmatics, The Klezmer Conservatory Band and others have mastered traditional styles while developing contemporary arrangements. The modern klezmer revival has breathed new life into this ancient art form, while keeping it an active, creative tradition rather than a museum piece.

Sephardic Jews can be found primarily in Mediterranean countries, and they are largely descended from Jews who were expelled from Spain in 1492. The word Sephardic is derived from the Biblical Sefarad, which probably referred to the Iberian Peninsula, where modern-day Spain and Portugal are located. The Jewish community thrived in Spain for hundreds of years, developing a rich cultural legacy that was influenced by the Spanish and Moorish societies that shared the land. In 1492, the Catholic monarchy gave the Jewish community a choice: either convert to Christianity or be forcibly expelled. Countless thousands of Jews left Spain, and spread out across the Ottoman Empire heading towards Morocco, Turkey, Greece and other Mediterranean countries. The language of the Sephardic Jews, called Ladino or Judeo-Spanish, is based on the medieval Iberian languages Castilian, Catalan and Galician-Portuguese, blended with elements of Hebrew, Greek, Turkish, Arabic, and more recently with bits of Italian, French and modern Spanish.

Sephardic music reflects the rich legacy of thousands of years of cross-cultural interaction. Elements of medieval Spanish music are evident alongside Middle Eastern rhythms and melodies, as well as Greek, Turkish and Moroccan instrumentation and influences.

The third major strand of Jewish music is less distinct and often is categorized as part of Sephardic music. Mizrahi literally means "Eastern" and it refers to the Jews who lived among the Arabic cultures of Yemen, Israel, Egypt, Jordan, Syria, Lebanon, Iraq, Iran and as far east as India. The main language used in Mizrahi music is Hebrew, although songs in Arabic are also common. Mizrahi music has come into its own recently in Israel, and artists such as Ofra Haza have become immensely popular. The music has a decidedly Middle Eastern flavor in its instrumentation, rhythms and melodies. Although often lumped together, Mizrahi music has a different historical and cultural background than Sephardic music. For example, there are no Spanish influences or use of Ladino.