Watching musician Andy McKee play is a delight for both eyes and ears, since his harp guitar sounds as wonderful as it looks, as you can see/hear when he plays Jeremy Soule's “Streets Of Whiterun” from the Skyrim soundtrack.
Andy's magical instrument was made by Greenfield Guitars in Montreal, Canada, and proprietor Michael Greenfield shared a bit about the instrument's composition:
My harp guitar has its own, proprietary body shape and many unique features. While inspired by the early 20th century harp guitars, this is truly a contemporary instrument incorporating all of the modern physics and design features found on all of my guitars. …My harp guitar is made of a laminated rim set, with laminated linings and a system of aerospace composite carbon fibre trusses and buttresses. This makes for an extremely rigid and stable skeletal structure. The soundboard is lattice braced. The Laskin style extended arm rest is included, as is a mini-rib rest on the rear of the pointed section of the upper bout.
-Via Laughing Squid