An experimental study was conducted to determine the effect of music and induced mental load in a word processing task. Eight subjects participated in the study. A 2x2 repeated measure design was implemented, with or without background music and with or without induced mental load. Applied typing force, typing productivity, and electromyography (EMG) of the left hand extensor digitorum muscle were measured. A computer algorithm detected the patterns of typing force, which were the cause of variability of typing force. Although overall typing productivity was compromised by music, the beneficial effect of music appeared to be a reduction of wrong finger touch during typing. The behavior change by music resulted in an increased extensor digitorum muscle activity for lifting and controlling fingers. This study contributes to the field of utilizing music to influence human performance in the workplace.