Bartok - Bulgarian Dances

 It is possible to learn much about composition from Bela Bartok's Mikrokosmos as it is to learn playing piano through it . Here is a recording of Bartok himself performing the Six Dances in Bulgarian Rhythm. And here is each one individually with the score: 1 2 3 4 5 6. And here is a jazzy arrangement, and another one.
Traditional Bulgarian vocal music (in a good arrangement performed by a fantastic choir) uses interesting rhythmic and harmonic practices.