Authors:

The sound of the mandolin is a very curious sound because it's cheerful and melancholy at the same time, and I think it comes from that shadow string, the double strings.

Rita Dove, Earl G. Ingersoll (2003). “Conversations with Rita Dove”, p.141, Univ. Press of Mississippi
The sound of the mandolin is a very curious sound because it's cheerful and melancholy at the same time, and I think it comes from that shadow string, the double strings.