This is for Windows users.
Sometimes you need to send MIDI messages to more than one application at a time at once. However, most MIDI drivers on Windows don’t allow you to open one MIDI port multiple times. So you have to toil around in both applications turning on and off a particular MIDI input. For MIDI outputs, same principle applies.
There is a workaround using two utilities together.
- First, setup loopMIDI from Tobias Erichsen: loopMIDI | Tobias Erichsen. Create two virtual MIDI cables, let’s say cable-a and cable-b
- Then setup TXL20 MidiRouter: MIDI Router - TXL20. You have to register, but apart from that, it is free
- After this, make sure loopMIDI is running. Then open the applications
- Assign cable-a to application A, for example GP (Options → MIDI Ports…)
- Assign cable-b to application B, for example Reaper (Options → Preferences… → MIDI Devices
- Make sure each virtual cable is connected to only one of both applications!
- Connect the MIDI device which messages you want to send to both applications, if you had not already done so.
- Make sure this device is not connected to any of both applications!
- Now start MidiRouter. A GUI is being displayed, listing all available MIDI incoming (on the left) and MIDI outgoing (on the right) devices
- Click on the MIDI incoming port of the device of step 7. It will be no longer grey, but colored and enabled.
- Click on the cable-a and cable-b devices on the right to enable these as an output
- Draw lines between the in port and the outputs (cable-a and cable-b). You need to click in the small circle next to the device and then draw the line in the same way as in the wiring view of GP
After this, the created routes will show up on top of the MidiRouter window and messages will be sent to both applications. I’ve created a small instruction-video which shows the configuration of TXL20’s MidiRouter: