The VL-1 was the first instrument of Casio's VL-Tone product line, and is sometimes referred to as the VL-Tone. It combined a calculator, a monophonic synthesizer, and sequencer.
Released in June 1979, it was the first commercial digital synthesizer, selling for $69.95.
It has 29 calculator-button keys (G to B), a three-position octave switch, one programmable and five preset sounds, ten built-in rhythm patterns, an eight-character LCD, a 100-note sequencer, and a multi-function calculator mode.
The VL-1 is notable for its kitsch value among electronic musicians, due to its cheap construction and its unrealistic, uniquely low-fidelity sounds.
The VL-1 was followed by the VL-10, a very similar machine in a smaller unit, and the VL-5, a polyphonic version, capable of playing four notes simultaneously, but lacking the VL-1's synthesizer section due to the removal of the calculator mode.
The VL-1 acquired enduring notability in 1982, when the German band Trio used it in one of their songs, the "faux-Kraftwerk tune", "Da Da Da".
They used the Rock-1 rhythm preset and the Piano voice.