MIDI issue when app is not in focus

[pat17]

Hi all

First of all sorry for my bad English as this is not my mother tongue. And also sorry if my question has already been raised, yet I couldn't find any similar thread when searching with key words...

I'm facing a very weird problem.

I am using the Motu MicroLite as an interface between my organ console and the virtual organ software Hauptwerk. For those not knowing it, it's quite simple - each time I'm playing a note on the organ, it sends a MIDI signal which tells Hauptwerk which note to play with which registration.

When playing, I used to be reading the music sheet on MusicReader (MIDI de-activated as not needed).

Recently I tried to upgrade from OS X 10.10 to OSX 10.11 El Capitan. All went fine, excepted the MIDI flow. When I tried to read the music sheets - meaning the focus was on MusicReader - it was fine for a few minutes, then the audio was stuck. Nothing could be played any longer, despite the MicroLite was still working - flashing when a key or whatever part of the organ was depressed - but no sound coming from Hauptwerk. When bringing back Hauptwerk in focus, all the stuck instructions were instantaneously released and I could go on till the next issue.

I tried to contact MusicReader support, which on the basis of the activity logs concluded nothing was wrong with their software. Same for Hauptwerk. I tried to download the Motu USB/MIDI new drivers (Feb. '16). No success.

I tried then to come back to Yosemite through the Time Machine. Success for the process, failure to solve the issue. Tried several workarounds (including but not limited to activating MIDI on MusicReader, restricting MIDI on Hauptwerk, etc...), still no success.

I then tried to upgrade to El Capitan again. No more success. And this time I coudn't come back to Yosemite, the process hung at the very end of the it. I re-installed the Mini completely from scrap - clean installation of Yosemite from a version downloaded on the App Store. Re-installation of Hauptwerk, the instruments, MusicReader.

It came even worse. Before I could play without MIDI issue if other apps rather than MusicReader were in focus - tried with Reaper, Garage Band, Preview, etc... which were fine. Now, if Hauptwerk is not in focus, and even if no other app is running, it will simply do not work.

I completely fail to understand what is the issue. I don't know what to try next...

Does any one has an idea of where the problem could come from, and how to solve it?

Thanks in advance for all suggestion / comment / other...

[stubbsonic]

First of all, you did an excellent job of describing your issue!!

I do not know what is causing the issue, but there might be some issue with the apps conflicting over their use of the MIDI driver.

I have a workaround suggestion. It is possible to keep an app "UP FRONT" while minimizing its windows. You could keep your organ app in the front, but press the yellow buttons in the upper left to minimize the window. This way you can see the other app's windows even if it is background.

Or you could print your notation?

Good luck.

[mikehalloran]

A similar to Stubbs workaround, I'd try a second monitor. I do things like this all the time, working with one app in the foreground while reading from a second monitor (I do a lot with documents in my job).

Neither fixes the issue, of course, but they do let you get your work done.

Back to the problem. Console.app should reveal the problem. It will tell you what is loading or what is failing to load. Open a window, then fire up DP and Hauptwerk plus whatever you are using to read the music. As soon as you experience the problem, stop.

All events in a Console window are time stamped. You want to copy only the event sequence that begins with opening DP and ends with the problem. Copy that much and paste into a Tech Link at MOTU Support. See if they can isolate the problem.

[pat17]

First of all, you did an excellent job of describing your issue!!

Thanks for the kind words... Actually this came naturally as I started to get used to writing to all technical supports in turn...

I do not know what is causing the issue, but there might be some issue with the apps conflicting over their use of the MIDI driver.

I got the answer at last - from Hauptwerk tech. support. The culprit was 'app nap'. They provided me with a link on how to de-activate it for all apps -

http://osxdaily.com/2014/05/13/disable- ... -mac-os-x/

And it worked like a charm. For the first time since too many weeks, I was able to play without any MIDI issue...

[pat17]

Back to the problem. Console.app should reveal the problem. It will tell you what is loading or what is failing to load.

Thanks Mike, I shall keep the trick in store for the next time - sincerely hoping there will be no next time...

[mikehalloran]

I got the answer at last - from Hauptwerk tech. support. The culprit was 'app nap'.

That makes sense. As many times as we suspect it could be the problem around here, this is the first time I can remember that it really was.

Thanks for posting both the problem and the solution. It will help others.