In short, sutartinė is kind of multipart song performed by women(usually 2-4 singers); there can be elements of dance and playing some instruments in it; tradition of sutartinės come from NE Lithuania; since 2010 they are on UNESCO Lists of Intangible Cultural Heritage
Short article about sutartinės
Material about sutartinės
https://www.youtube.com/watch?v=Wij_cgVGOxw
Another example of sutartinė
https://www.youtube.com/watch?v=zeEnhlRteiA