I've been thinking of adding some Bulgarian folk music to my own selection.Does anyone have any good suggestions? What is the best of the best in this genre?

Three or Four years ago on vacation, I remember going to some lantern festival in Victoria (Vancouver Island).There was folk singers in different parts of the park and my favourite was these young Bulgarian women who sang a cappella.They sang a very interesting vocal harmony, sounding both melodically pleasing and wild.It contained a droning quality that reminded me of bagpipes, with hints of the middle east.I've heard this type of music before with The Bulgarian State Radio and Television Female Choir, though the singing was probably less polished.

I know there's more to Bulgarian folk than just women singers or a cappela, though that is my exposure so far and I defenitely want to hear more of that particular sound! Any suggestions of more modern takes on traditional Bulgarian are also welcome.