Bartók: String Quartet No.6, Sz.114, BB.119

Béla Bartók (1881-1945): String Quartet No.6 in D minor, Sz.114, BB.119 (1939)
The quartet is in four movements:
I.    Mesto – Più mosso, pesante – vivace
II.   Mesto – Marcia
III.  Mesto – Burletta – moderato
IV.  Mesto