I'm using an Ketron FS13 pedal that can be programmed with a lot of different things. Pressing the "Menu" and go into the menu "Keyboard Control -> Footswitch"and here you make the desired programming. For example, "Regis Up & Regis Down". You can then with the foot pedal run up and down in the requested registrations without stopping keyboard. In a medley, you can for example play 5 different melodies in 5 different tempo and styles and voices without stopping the keyboard by doing 5 different registrations and then change them with the foot pedal.
Henning - Denmark