This song is in DT under the title "The Saracen," but it looks like the DT got it from the above message!

The real title is "I'll Hang My Harp on a Willow Tree," and it was written by the English poet-dramatist Thomas Haynes Bayly (1797–1839).

The University of North Carolina at Chapel Hill's Music Library has images of the sheet music on its web site. Search this page until you find "I'll Hang My Harp on a Willow Tree" and then click on one of the links to see any page of the sheet music.

The Library of Congress has several copies of the lyrics.

It was recorded by Christina Smith, Brown Ale, Orchid, and Walter Pardon.