Susanne, noter-drone music uses a noter (usually a wooden peg or stick) to play the strings. The most common string set up is to have 2 melody strings, 1 mid-range string, 1 bass string. DAA or DAD are the most used tunings. You use the noter to only play the notes on the melody strings while letting the other strings 'drone'. Some players can really make wonderful music using this style. My attempts make my ears hurt!
This style can have many variations in setup. I never cared for the concept enough to dig deeper than the basics.