hmmm...i don't know very much about that, but as far as i know midi controler is used via a sound card to the pc and sounds acording the program andplug ins you are using (independently on the sensitive touch of the controller, thats another thing) So you need a program or virtual sintetizer that reproduces an arpegiator, every midi controller can be an arpegiator or a 1000 more effects depending on the program you are using..I think that i works that way...am i wrong?
cheers
Toni