I often use a phono fiddle live (one string, with a brass horn) Sometimes play a ukelin (32 string US depression-era thing) Various zithers and autoharps (bugger to tune) Dulcimer (gets a live outing on occasion) Psaltery (as above) Lute guitar (scalloped frets) Bell harp (12 string instrument which you swing while you play...used it a couple of times with'mickel mass') Cuattro 12 string mandolin VL-Tone & PT20 keyboards Clarsach French horn etc