I didn't know what to expect on the Everly Brothers cover by Norah and Billie Joe but I loved it. I'm a fan of the Everly Brothers particularly for those amazing two-part harmonies. Their style was carried on by Simon and Garfunkel and we hear it much later the Finn Brothers**.
I recently purchased the Original Album Series collection of the Everly Brothers. In the same shipment was a superb debut CD of another duo who call themselves Winter Mountain (an intro here http://www.bbc.co.uk/news/uk-england-cornwall-12970028). They were the first to be signed to the Charcoal Records label owned by Sam Lakeman and his wife Cara Dillon. They are more active on Facebook https://www.facebook.com/wintermountain than at Twitter or their website (but I won't hold that against them).
Just to give you a feel, here's a live performance of "Whenever You Lay Your Head Down" that I found:
Also worth checking out are their videos for Shed a Little Light and January Stars.
Getting back to the topic of Kina Grannis and Marié Digby will "The Keeper" be on the album of either of the two or is it a stand-alone single?
I see that Marié has shot a video in Ireland:
can't wait to share it with you soon! Have a beautiful day xo
Steverino