Thats a feature i'd like as well. Following options would be good (if could be configured per cart): - Start a cart by midi note. - Stop a cart by midi note. - Toggle a carts play state by midi note. Besides receiving midi notes to trigger carts, sending midi notes if a cart gets triggered would also be great. Even better if you could define a different midi note being sent for starting than for stopping(only send midi note if clicked to stop a cart, not if it normaly finishes playing) a cart. This would add a huge benefit to Cartwall for interconnecting with other applications.