A stringed musical instrument includes a musical instrument body configured such that a string is attached thereto. The musical instrument also includes a pickup configured to detect vibration of the string and output a string vibration signal according to the vibration. The musical instrument also includes a detection sensor that is attached to the musical instrument body and configured to output a detection signal according to a force applied to the musical instrument body. The musical instrument also includes a controller that is attached to the musical instrument body, and is configured to output, based on the detection signal, a control signal configured to control an operation of an effector configured to impart an effect to the string vibration signal.