They are Maggie & Terre & Suzzy, Maggie & Terre & Suzzy Roche. They have enchanted me with their amazing and interesting harmonies since I first heard their music, via my friend Allen Moyer, back close to 30 years ago, when I was still in college and Allen was designing a set we were working on. Allen went on to be nominated for a Tony Award for his design of Grey Gardens in 2007. I was an instant fan of the sisters, and their holiday album, We Three Kings, is one of my favorites of the season. I hope you enjoy this clip of them singing an assortment of those songs.
And, in keeping with the spirit of the holidays, here they are singing The Hallelujah Chorus in 1982, live at the Improv in New York City.
You can find out more about The Roches on their website.