Because of the "Makeup Tools" functionality, Roland's are some of the best and easiest arrangers for playback of MIDI files. They can also perform real-time chord extraction from MIDIs. The G70 generation (including the E50, E60, E80) has a live score display too, so if you want to play along, all you have to do is "follow the bouncing ball!" After this, Roland ditched the touch screen and subsequent generations lost this feature.