An interesting counterpart of mandolin orchestras are Russian balalaika orchestras. Like members of the mandolin family, balalaikas are double strung, and for an orchestra, come in soprano (violin), alto (viola), tenor (cello) and bass ranges. A bass balalaika is a truly awesome sight to behold; at least it has a flat side to set on the floor (they're triangularly shaped, with the neck at the apex). It's played standing up, like a string bass.

There are a slew of double-strung instruments that are in the same tone range, some 8-string and some 10-string. Bouzouki, octave-mandolin, mando-cello and cittern all seem to be in the tenor range; I think the only differences are the shape of the body and the way the strings are tuned.

Jeff Davis, an American instrumentalist and traditional singer, has a beautiful Gibson mandocello which sounds wonderful as an accompaniment.