A type of synthesizer control device that responds to changes in voltage or resistance caused by moving a finger along its surface. Some ribbon controllers are also able to record pressure or velocity.
The ribbon controller has a long and distinguished history in electronic musical instruments. In 1928 Maurice Martenot, a French radio operator, presented a new electronic instrument, the Ondes Martenot (“Martenot’s Waves”) that included both a seven-octave keyboard and a ribbon controller that allowed pitch inflections like a voice or stringed instrument. It allowed for a wide glissando when the player moved a finger ring attached to the metal ribbon that controlled frequency. Hundreds of symphonic works, operas, ballets, and film scores were composed for this instrument. A different instrument incorporating ribbon-style pitch control, the Trautonium, was introduced in 1930.
The basic design of a ribbon controller is fairly simple. In most cases it is a linear potentiometer that generates different control voltages depending on where it is touched. Think of it as a rotary knob that has been “unrolled.” It’s made of an electrically conductive strip that senses the static discharge that occurs when you touch it. These changes in voltage can be applied to any number of voltage-controlled oscillators, filters or amplifiers in analog synthesizers. The voltage fluctuations can also be translated into binary data and used to control digital modulation.
Some ribbon controllers include a velocity or pressure sensor, often made of conductive rubber, which generates a second control voltage that increases with pressure. Again, this voltage can be assigned to control many different parameters of a synth patch.
Rock and Roll embraced Moog ribbon controllers in the 1960s. Keith Emerson was famous for attaching a Moog ribbon to a pyrotechnics control, using both simultaneously to set off both musical and literal fireworks. The famed “Theremin” sound in the Beach Boys’ song “Good Vibrations,” was in fact played by a ribbon-controlled instrument called the Electro-Theremin. The Beach Boys themselves later used a Moog ribbon controller with a Moog synthesizer in live performances.