Inscribed in UNESCO’s List of Intangible Cultural Heritage in 2017, rebetiko music synthesized Anatolian and Greek musical traditions into a form of “Aegean Blues”. Rebetiko initially spread among the urban lower and working-classes of Athens during the early 20th century, thriving with the arrival of Greek refugees from Asia Minor in 1923. Rebetiko songs contain invaluable references to the customs, practices and traditions of a particular way of life, but above all the practice is a living musical tradition with a strong symbolic, ideological and artistic character. Filled with insightful interviews and energetic performances, Rebetiko Underground looks at the state of the genre today in both Greece and Brussels, which has a thriving rebetiko music scene featuring musicians of diverse nationalities who have been attracted to this musical traditional. As one of the musicians interviewed says, “Rebetiko was World Music before World Music existed.”