The Radiodrum or radio-baton is a musical instrument played in three-dimensional space using two mallets (snare drum sticks with wires). It was developed at Bell Labs in the 1980s (and patented), originally to be a three-dimensional computer mouse. Currently it is used as a musical instrument similar to a MIDI controller in the sense that it has no inherent sound or effect, but rather produces control signals that can be used to control sound-production (or other effect.) As such, it can be thought of as a general telepresence input device. The radiodrum works in a similar way to the theremin, which uses magnetic capacitance to locate the position of the drumsticks. The two mallets act as antennas transmitting on slightly different frequencies and the drum surface acts as a set of antennas