Abstract: A hand-held controller (100) for a computer is disclosed. The controller is substantially U-shaped and has front and IN rear sections (110, 130) spaced apart by a link section (140). The controller fits onto the user's hand in use so that the rear section (130) lies over the back of the hand and the front section (110) lies in the palm of the hand. The front section includes a user interface, such as a keypad, touchpad or touch area (120), to receive inputs from the user's fingers. The controller may also include a gyroscope and an accelerometer to determine the orientation and movement of the controller. The controller further comprises a transmitter for transmitting data relating to the user inputs to the computer, the data causing the computer system to carry out one or more pre-assigned actions. The pre-assigned action may comprise playing or altering an audio sound, or changing the key, pitch, tone, sound quality or volume of the audio sound.