Reason is a great application, but it does not let you route MIDI events from one plug-in to another.
Here is a video tutorial that shows how to use PatchWork to connect MIDI plug-ins and virtual instruments together, so that you can enjoy smart MIDI plug-ins such as Instachord or Scaler inside Reason.
Of course, as mentioned in the video, this applies to many other hosts applications such as AKAI MPC or Maschine.
Enjoy!
