Last time, we began talking about some of the things we can do with MIDI and how the note structure works. If you missed that post, go back and read it now. It’s OK, we’ll wait. Got it? Good. Moving on…

Channel Designation for Organization

Given that we have 16 channels available, I decided to assign a channel to each computer in the booth. ProPresenter is channel 1, the Hog is channels 2-3 (in case I want to do more than 128 things with it—I think big…), and audio control is channels 4-5 (again, thinking big). Mixxx is on channel 5, channel 4 is currently not used. 

So let’s take the Hog for a moment. To press the virtual “Go” button, I send a Channel 2 Note-On 50 with a value of 1. I’m not sure why, but a 0 value won’t work. I suspect anything above 1 would also work, but 1 does the trick. For simple button presses, the right Note-On with a value of 1 will typical work. Most lighting controllers will respond to MIDI commands; check your documentation (or Google it) to figure out how to your system works. Here’s the link for the Hog documentation.

In ProPresenter, I’ve designated Note-On 32 as the start message clock. So from the SD8, I send a Channel 1, Note-On, Note 32, value 1. 

But wait, there’s more! 

Some things can accept more than one value. Take a ProPresenter presentation with 37 slides in it (a totally random number I just grabbed out of thin air). I’ve set up the Trigger Slide command up as Note-On 21, but I can access any of those 37 slides by specifying a value between 1-37. So maybe the message video package is the 5th slide in that presentation. By firing a Note-On 21 with a value of 5, I would trigger that slide directly. So the video rolls right as the audio snapshot is fired. 

Or in Mixxx, the thing we ran into one weekend was with the crossfader. Because it’s a DJ app, it’s designed to let you fade back and forth because the two virtual “Decks.” Our problem happened when the last song of the walk in set landed on Deck B. When I fired the walk out snapshot, Deck A started up, but no sound came out because the crossfader was all the way over on Deck B. But we can fix that. 

The crossfader can be controlled by MIDI. I assigned Note-On 3 to the crossfader. A value of 0 is full Deck A. A value of 127 is full Deck B. So can you guess what I send to Mixxx now in my walk out snapshot? 

  • Channel 5, Note-On 3, 0 (pull the crossfader to full Deck A)
  • Channel 5, Note-On 1, 1 (play Deck A)

And also…

  • Channel 1, Control Change 3 (stop recording and save all tracks in Reaper)

Now, I know I said channel 1 was designated to ProPresenter, but Pro doesn’t respond to CC’s, and Reaper is already set up on channel 1 for CC’s and I didn’t feel like changing it. Maybe someday I’ll correct this gross inconsistency. 

Keep it Organized

To keep track of all the stuff I can now control, I’ve come up with this simple spreadsheet to remind me of the various commands I’m sending to where. It seems like a lot, but for the most part, the commands I’m using regularly are already part of my baseline show file, or saved as Macros and assigned to function keys on the SD8.


 This is my current master MIDI list. It’s a work in progress, but these are the commands we use regularly.

The cool stuff doesn’t end there. I’ve written before how I use AppleScripts to control things, and one of the fun features of MIDIPipe is it’s ability to fire an AppleScript in response to a MIDI command. So my next project is an AppleScript to start the video recording in Media Express, which will of course be fired by a MIDI command, which is fired from a snapshot on the audio console. 

I should also note that I’ve held off writing about this for a few months because I wanted to see how stable it would all be. I’m actually pretty surprised that it’s worked flawlessly for the last two months. The only issues we’ve had have been when we forgot to make sure the network nodes were all connected before service started. I’ve run lights from audio for two full weekends without a single glitch. And the walk out music starts right on cue every time now. So it’s pretty solid, overall. 

What Does It Look Like?

Here’s a screen shot of my MIDI list from last weekend. We were without a lighting guy, so I ran lights from the SD8 (a practice I don’t recommend—it’s a very high workload—but you do what you have to do).

This is a glimpse into the madness that goes on in my head every weekend… 

Let’s look at the last two snapshots. 39.50 is a live walk out that brings the band back up to play out of the service. That Channel 2, Note-On 50, Value 1 advances the lighting console to the next cue (the walk out look). In snapshot 40, we do three things; crossfade to Deck A, start Deck A playing, and tell to Reaper stop recording and saves all tracks. Of course, snapshot 40 also fades down the band DCAs (in 3 seconds) and fades up Mixxx in 6 seconds. 

You’ll also notice a bunch of snapshots that start with —L… Those are my lighting snapshots that don’t do anything to the mix, they simply fire the MIDI command that advances a lighting cue. To keep track of where I am in the cue list on the Hog, I set my iPad on a music stand next to me with an open VNC connection to the Hog. 

Wrapping Up

So that’s my week of MIDI primer posts. I once considered MIDI somewhat mysterious, but it’s really easier than I thought. You may wonder why go to all the trouble to set it up when we have volunteers to run all the other gear in the booth. The answer is two-fold. First, I did it because I can (sort of why mountain climbers climb Everest—because it’s there). Second, we’re in a season of being short on volunteers. And the show must go on. Only now, it can be done with fewer people. Plus, it’s just really cool…

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