It is very complex and stressful task to play musical instruments, creating fine music. Professional musical players often complain of difficulties in manipulating their instruments skillfully. In these cases the fingers are found to be hyperflexing, upper limbs are in abnormal posture. This phenomena is named as Musician's dystonia, due to abnormal sensory-motor integration concerning manipulation of musical instruments. It is a regret for the patients that few medical doctors pay attention to the disease and misdiagnose as psychiatric problem or others very often. The hyperactivity of finger muscle should be reduced precisely. Botulinum neurotoxin is effective to treat such hypercontraction of muscles, however, in case of musician's dystonia, too much amount of its effects are not beneficial for the players because of the risk to weaken or paralyze the finger/hand becomes higher. We are trying lidocaine injection into the muscles in charge of dystonic posture/movement successfully.