Here's a song that shows why they have the special made guitar.....the "frets" extending into the guitar opening below the strings and two versions recorded at two stages in their life.....
To play the included videos in the above entries, you'll have to click the "blue box" with the www.YouTube.com link designation...this will bring it up for you to view....don't know why the photo is missing...here are a couple more that are beautiful.: