Plug the bigger end of your USB cable into your computer. The port is located on the side of laptops and the back of desktops. Plug the smaller end of your USB cable into your MPC controller, also at the side or back.
Open Reason. Select the Preferences menu. On a Mac, this will be in the top menu under "Reason." On a PC, look to the top menu under "Edit."
Select "Advanced" from the drop-down menu at the top of the Preferences window. Under External Control, select your MPC MIDI controller from the "Bus A" drop-down menu.
Click "Keyboards and Control Surfaces" from the drop-down menu at the top of the Preferences window. Locate your MPC controller from the list and select "Use with Reason." Select "OK" and close the preferences window.
Select the "Advanced MIDI" panel at the top of your rack. Click "MIDI Channel 1," and choose which instrument you would like to control with your MPC. Once this is selected, you will be able to use your MPC controller to play an instrument or alter an effect. Assign different instruments to different MIDI channels on the "Advanced MIDI" panel to control them with your MPC.