The music of Southeastern Europe or Balkan music is a type of music distinct from others in Europe. This is mainly because it was influenced by traditional music of Southeastern European ethnic groups and mutual music influences of these ethnic groups in the period of the Ottoman Empire. The music is characterised by complex rhythm.

The music of the Slavic countries of Southeastern Europe is significantly different from the music of Eastern Europe, which includes the Slavic states of the former USSR. The latter was much more influenced by the common eastern Slavic culture, notably by Kievan Rus and more recently the USSR.

Byzantine (Greek: Βυζαντινή Μουσική), traditional music is associated with the medieval sacred chant of Christian Churches following the Constantinopolitan rite. Its modal system is based on the ancient Greek models. The development of large scale hymnographic forms begins in the fifth century with the rise of the kontakion, a long and elaborate metrical sermon, which finds its acme in the work of St. Romanos the Melodos (sixth century). Heirmoi in syllabic style are gathered in the Heirmologion, a bulky volume which first appeared in the middle of the tenth century and contains over a thousand model troparia arranged into an oktoechos (the eight-mode musical system) and the whole system of Byzantine music which is closely related to the ancient Greek system.