I'll also suggest mandolin. I have one that someone thought was called a pocket mandolin. It is 23" long but only 5" wide (Just wider than the bridge.) and less thatn 2" thick. The problem might be finding one. I have only seen mine and one at the 12th Fret. However, now that you know such a thing exists you could call around. Mine has no markings to indicate who made it or when. Oh, and it only cost me $50.00CDN. My other suggestion would be a banjo mandolin Peter. Do you remember the one Davie had at the Tranzac? Lark In The Morning has one for $95.00US on their Mandolin page.