A musical instrument includes a resonating pipe having a first slot defined along a length of a longitudinal axis of the resonating pipe and a sliding rod that slides along a length of the first slot and closes the first slot such that the sliding rod selectively covers and provides an air seal to the first slot, such that a pitch of sound produced varies according to a length of closure of the first slot. A mouthpiece is coupled to the resonating pipe to enable the player to create a resonating column of air in the resonating pipe and control the pitch of the instrument by controlling the coverage of the sliding rod over the first slot. A composite musical instrument may include the wind instrument combined with a stringed instrument.