A musical-tone-control apparatus having digit members worn along the fingers and contracting and expanding in the longitudinal directions of the digit members in response to the bending and straightening of the fingers. The bending of the digit members is detected by detectors coupled to the digit members and the generation of musical tones is controlled on the basis of the detected signal, i.e. the bending of the fingers. The contraction and expansion of the digit members facilitates the bending and straightening of the fingers. The digit members can also rotate in a plane of the hand to further facilitate the movement of the fingers. The digit members are made to bend about the axes positioned on the third joint of the fingers or the second joint of the thumb (the joint just below the root of the fingers or the thumb), which makes the bending of the digit much easier. A palmar member that supports the digit members are curved to conform the shape of the palm, which makes the bending of the fingers easier as well as preventing the displacement of the palm member.