The range is beautiful, the darkness, muted solitary calls. Some of the most beautiful music I have ever heard. This is romanian folk singer Maria Tănase singing Doïna de Dolj.
Doina is a free-rhythm, highly ornamented (usually melismatic), improvisational tune. The improvisation is done on a more or less fix pattern (usually a descending one), by “stretching” the notes in a rubato-like manner, according to the performer’s mood and imagination (says wiki).
Doina is one of Romania’s items in the UNESCO list of Intangible Cultural Heritage.