Method and apparatus for controlling musical sounds by player's foot movements

A musical sound controlling apparatus to be placed inside a shoe and operated by the foot of a user. The musical sound controlling apparatus has a substrate plate and at least a piezoelectric sensor device. The substrate plate and the piezoelectric sensor device include a pair of hook and loop pads for detachably connecting the piezoelectric sensor device and the substrate member. Upon depression of the piezoelectric sensor device by the foot of a user, the piezoelectric sensor generates a signal for controlling musical sounds. Furthermore, the substrate plate is divided into two separated sections, a toe section and a heel section. A size adjusting device slidably couples the heel section to the toe section so that the overall size of the musical sound controlling apparatus can be changed according to the size of the shoe.