From this blog (http://www.austinchronicle.com/music/2012-03-16/spotlights/):
"....Clark's impressed Paul McCartney, jammed with the Roots on Late Night With Jimmy Fallon, and collaborated with Alicia Keys, that last one inspired by the R&B singer discovering Clark's rendition of "While My Guitar Gently Weeps" with Will Taylor & Strings Attached.
"She saw a video on YouTube of me doing the song down in Austin," he confirms.
Here’s that video http://www.youtube.com/watch?v=sl4AZtLZe6o
Buy the album with that song here: http://www.cdbaby.com/cd/wtaylorsa2