<qa>  What is the purpose of the study?This study uses a computerized method of musical instrument digital interface MIDI quantification of performance before and after treatment with botulinum toxin type B Myobloc , Solstice Neurosciences. Myobloc is a purified and diluted form of botulinum toxin used medically to relax unwanted muscle spasms and movements. The aim of the study is to determine the feasibility of quantifying change in performance following treatment. 