The CT-701 featured the Melody Guide function, using LED lights to show the user which keys they should press in order to play a song. Songs could be loaded into the keyboard as musical scores in barcode format and stored in memory, a world-first feature. The CT-701—born of a new concept unlike any other instrument of the time—was a pioneering instrument that even a complete beginner could enjoy playing with ease. It was the predecessor of the Key Lighting function and started the evolution of methods of loading in songs the user wished to play.