Folk music was popular in the 1970s in Uruguay, but has been on the wane for decades. Now three singers are re-imagining it and making it cool. And they’re bringing their tunes to the popular SXSW music festival.Folk music was popular in the 1970s in Uruguay, but has been on the wane for decades. Now three singers are re-imagining it and making it cool. And they’re bringing their tunes to the popular SXSW music festival.