This culture is very roughly described as maqam music shaped by Western influence. The music is modal with scales like phrygian (kurd) or double-harmonic major (hijazkar). Yes it's in 12-tone temperament, as the instruments are fretted strings, brass, accordion. Sometimes droning bases or major/minor triads are used as harmony.
- Matthew James Kay. A Return to Brotherhood: Nationalism, Globalization and The Negotiation of Identity in Romani Brass Band Music in Serbia - The author describes his visits to a Guča festival and to a Romani village to interview musicians
- Bulgarian Fake Book
- https://www.folkloretanznoten.de/
- https://trillian.mit.edu/~jc/music/abc/Bulgaria/
- http://musicart.imbm.bas.bg/izbor.asp
- https://youtube.com/@gerganof
- Kalin S. Kirilov. Bulgarian Harmony. In Village, Wedding, and Choral Music of the Last Century
Петър Стоянов. Българска народна песен: тоналност, лад и мелодика- https://docs.google.com/document/d/1WsOwF66Cz6pFefQG0P09vULGJXYoxdFjkIZ8jW8Ofb4/edit
- Risto Pekka Pennanen. Westernisation and modernisation in Greek popular music
- Also "The Development of Chordal Harmony in Greek Rebetika and Laika Music, 1930s to 1960s" and maybe other papers
- Hans Baken. Folk Music from Bulgaria, Fake Book
- Maqam: Historical Traces and Present Practice in Southern European Music Traditions. Edited by Jürgen Elsner, Gisa Jähnichen and Jasmina Talam
- https://www.pelister.org/folklore/songs/index.php
- klezmer