Connect the FS13 (13 switches) and program them to each do 1 of over 50 functions available on the AUDYA 4 (e.g. Switch 1 = Start/Stop Drums, switch 2 = change voices, switch 3 = turn on/off vocalize, switch 4 = scroll through lyrics, switch 5 = sustain for piano voices, etc. As you play your guitar, simply step on a switch to control AJAMSONIC AUDYA 4