If you are like me, you practice at home, have a large dog, and he makes regular visits for attention while you are working. ALWAYS wash your hands after touching your pet during practice (on a string instrument). Sounds silly but not at all!! Many dogs possess a coat rich in oils for protective purposes. When these oils emulsify with the moisture from your hands, the result is a grease that forms between the windings of your strings, and will instantaneously stifle the string’s resonance .