Narciso Yepes' 10-string is one heck of a guitar, but I would go for the 11-string "Alte-Guitar," or "alto guitar" made by Georg Bolin of Stockholm, Sweden. I first heard about it when Barbara gave me a CD of Swedish guitarist Göran Söllscher playing music for the Baroque lute—on an 11-string guitar. Here's a clip from YouTube with Söllscher and his instrument. CLICKY.   Another look at the guitar HERE.

The guitarist in the photo says the following:   "This is my 11 string alto guitar, made by Georg Bolin in Stockholm, anno 1979. A unique guitar, extensive as a renaissance lute. It's fantastic for playing music by John Dowland, one of my all time favourite musicians. For ballads and some Bossa Nova tunes, my alto is supreme. Generally, the alto guitar is unique for accompaniment. Bass lines one can but dream of on a 6-string can be made real on this harp!"

I believe the top six strings are tuned like a standard guitar, but a minor third up (like a cap placed on the 3rd fret) and the basses just go down the scale from there. Basically, the same tuning as a Baroque lute.

Imagine the accompaniments one could do on a monster like this!

Don Firth