Roosebeck Descant Lute 7 Course 13 String Set Straight End RBSLTDC. Throughout history lutes have typically had gut strings. Lute strings today, however, are nylon made with high precision instruments. The rectified nylon strings in the Roosebeck set are known for their warmer tone and lightly textured feel. The silver-plated copper wound nylon bass strings also produce a very warm, classical tone. We recommend the traditional Renaissance tuning for this set.