Well if you wanted to trigger auto accompaniment obviously you would need to use a tone module that could do that like the Roland BK7m unless you will be using a computer then you could use auto accompaniment software instead ( see my links at http://www.synthzone.com/midiaccomp.htm for possible software solutions ). Either way you would still need the GR-55 as well to plug the GK-3 pickup into to provide MIDI data. So if you were using a computer then the GR-55 and software would probably work.