MOTU Digital Performer(2)

Objective: Extract and alter the feel of Dr. REX loops using DP’s MIDI editing. Background: Playing a REX loop from Reason’s Dr. REX into DP’s virtual mixer is easy, but it doesn’t give you much room for tweaking the feel or correcting the timing of the actual loop. Fortunately, Reason lets you export a REX file’s associated MIDI file, which you can then load into DP. From there you can apply groove quantization to the MIDI data, or use it as the basis of a new groove template in DP. Extracting the MIDI data for a REX file gives you much more control over your Dr. REX loops, and once you’ve tried it you’ll be hooked.


1. Create a new session in DP, then launch Reason and create a new session with a mixer and a Dr. REX player.

2. To hear our loop(s), we need to route audio from Reason into DP. In DP, create an Aux track (go Project menu > Add Track > Aux Track), then set its input to accept audio from Reason’s stereo mix bus.

3. Load a loop into the Dr. REX player. When you click on “Preview,” you should hear the loop play back through the aux track in DP.

4. Now export the REX loop’s MIDI file. Click on the Dr. REX player so it’s highlighted in the rack. Go to Reason’s File menu and choose Export REX as MIDI File. Save the file to your desktop — this will make it easier to drag-and-drop the MIDI file into DP.

5. To use this MIDI data to trigger the loop slices in Reason we need to create a MIDI track in DP and assign its output to Dr. REX. After you’ve set this up, drag-and-drop the MIDI file onto the Dr. REX MIDI track.

6. With the MIDI data inside of DP you’re free to use any MIDI editing or quantize functions to deconstruct or alter the loop. Alternatively, you can create a groove template by selecting the MIDI region and then choosing “Create Groove” from the Region menu.


-By working with Dr. REX loops as MIDI regions inside of DP, you can “conform” loops with wildly varying feels to one particular groove. Simply use the same quantization template on all of the MIDI files.

-As you have a MIDI track assigned to trigger Dr. REX, you can program your own patterns by playing the slices directly from a MIDI keyboard.