Basically they are violas, Mike, but they put flat bridges on them so that the players can play drone chords. Some of them do the same with flat-bridged cellos. They seem to call them "contras".... and Jack Campin is right; the best place to hear this is in the Gyimes valley region. Fabulous music in a beautiful part of the world. We were there just a few months after the execution of Ceaucescau and the place was one long on-going party when we were there.