Waren is an ornamental technique.
It is a light, quick stroke along the lower strings with the plectrum of the
third finger of the right hand. Standard practice dictates starting
with string 1 at the far right of the string, then ending up on the
fifth string by the end of the stroke. The actual strings stroked is
approximate: some performers will stroke strings 1-3, or 2-5, or vary
the exact pitches during the performance.