The Open Music App Collaboration Manifesto

Rolf Wöhrman, developer of the NLogPoly Synth line of iOS apps, has posted an  Open Music App Collaboration Manifesto, calling on iOS music developers to push ahead with inter-app collaboration features:

This is a doc about how iOS apps should use MIDI while running on same device. It provides a set of best practices which should make user experience as great as possible for people who want run apps in parallel like in these scenarios:

– A controller app (like SoundPrism, Polychord etc.) in front plays a sound generating app eg. a synth (like NLogSynth etc.) running in the background

– Two beat-oriented apps eg. a drum machine (like MoDrum, Molten, Funk Box etc.) is running in sync with another app (like NLogSynth arpeggio or BassLine etc.)

– A sequencer app controls other sound generating apps like synths, drum machines etc.

– An external MIDI controller plays a synth app running in the background while the iOS interface is used for an app in the front triggering loops

– Any combination of these scenarios: A sequencer app controls a drum box & arpeggiated synth in the background while the user plays controller app controlling another synth in the background.

An example is embedded above.

CPU & RAM are the only limits!

Wöhrman goes on to detail 7 ‘must haves’ for inter-app collaboration and 9 more options that are desirable.

He notes that “Most best practices described here are neither rocket science nor my inventions. I just tried to summarize what needs to be done to have a great user experience.”

What features do you think iOS music apps need most?

You can read the full manifesto here and there is also a Google group to discuss and refine the ideas.

24 thoughts on “The Open Music App Collaboration Manifesto

  1. interesting. good to see someone paving the way. Do we need jailbroken devices to run several music apps at the same time like this today?

  2. I support this effort, but two things: First, iOS apps were initially not meant for multi-tasking. Trying to mimic the DAW/VST workflow on an iPad makes little sense since computers are more powerful and provide user-access to the filesystem (If Apple would just do this, we would be much further ahead). Many of us want to ditch our laptops for iPads and I don't think Apple considered this initially.

    Second, I think iOS will become a traditional desktop OS anyways. It's possible that OSX and iOS will merge and be one product in the near future (Look at all the iOS stuff in Lion as well the expanded features rumored to be in iOS4). Microsoft has similar plans with Windows 8, as well.

  3. Saying iOS apps were initially not meant for multi-tasking doesn't mean anything.
    We're actively improving performance of our app (SoundPrism) and working together with other developers to make sure we're not using too many ressources.

    Please just give us a couple of weeks (not months – this will be available in September) to go live with this and then lets see how things develop from there.

  4. I see, thanks for replying. 🙂

    These apps are obviously high-end, and cost more than I'm willing to pay for a little experiment. Any low cost / free apps supporting this?

  5. Ok, just downloaded MoDrum. Allready had Bassline. This is cool!

    Next up I'd like to try is ExpressionPad and Mellotronics M3000 (though I doubt that last one has MIDI-support)

  6. Yes! YES!! YES!!!!
    this is the right direction.
    will be glad to beta test this for ye anytime and am more than available and passionate about music making, Innovation, sync and multitasking.

    Good Luck !

  7. So, just to set things straight, the stuff in the video is not yet possible without a developer version of SoundPrism Pro, right? I just installed the app, and couldn't find the option to turn the sound engine off.

  8. I have waited for this. Very good! Now I play loop in the background and Jordans app as a lead, but its no sync, but still wery nice. I hope more will evolve 🙂

  9. would be nice if my favorite music apps did this

    bebot, morphwiz, loop, samplewiz, reactible, loopseque, filtatron, aeolian harp, tnr-i, mixtikl (well they already do it, but no sync though), soundythingie, ielcectribe, ims-20, worldsoundmix, donut, nanostudio, addictive synth

  10. Yamaha has to sign Keyboard Arp & Drum Pad on to this and intua BeatMaker Pro. I just ran SoundPrism iPad2 thru Mac's midi network setup to my iphone4 beatmaker 2.1 But this should be much better.

  11. ^+1 ffs. I love NLogSynthPro, but it's still got MIDI issues that the guy never resolved. Instead he went on to create a plugin version of the software before fucking finishing his app. lol.

    It also pisses me off that he's riding the coat-tails of the devs at Finger and SyntheticBits – who pioneered this shit AND – with no small help from my constant urging – made all their CoreMIDI development findings public with several excellent blogs/tutorials.

    So while I applaud any effort to promote CoreMIDI and give devs a kick in the ass, the time that he took to do all this shit might have been better spent actually getting NLogSynth Pro up to speed.


    1. Hi,

      maybe some useful info:

      The iOS apps are in review with Apple with all the virtual MIDI, background audio, MIDI & WIST Sync stuff. Here is a list:

      In terms of new features, my todo list is very long with user requests, new ideas etc. Whatever
      I choose from for the next update, some will be happy, but also I will be punished by all the others.
      Since updates are free, I just cannot finance ten people to do all at once. I do my best to do
      every 3 (+/-1) months updates with new features.

      If you have outstanding issues in terms of defects, please get in contact by email with me to check
      if the new updates resolve them. (email via

      In regards to Finger and Synthetic Bits: I am in nice personal contact with them, and they are
      supporting the OMAC initiative and are fine with their recognition of the first ones. In the manifesto it is clearly written about them and given all praise to them.

      But the OMAC initiative goes much further. And it is an asonishing initiative where now more
      than 75 people (most of them are devs) are discussion open and positively without any hate
      about all these features. We are exchanging code in the group or in emails. I made some
      important parts of NLog’s MIDI code public as others did.

      We are exchanging beta versions to each other and helping in all sort of aspects.

      I did not foresee this, but it was and is an encouraging surprise how colaborative all
      the devs are.

      Don’t be afraid, we try to do our best.


  12. All development only versions: So far, I have been told that NLog can be driven by Geo Synth (which I did not need to change to accomodate it). SampleWiz is being updated to do background MIDI, and I have already done a little testing with it.

    This means that many apps that play the controller will already work as shipped, and it will mostly just be an issue of saving memory and shutting off internal sound engines (not just zero volume) in the event that we now have 4 of these things running at the same time.

    The sound generation apps need to be updated to support virtual MIDI ports. And while I guess LSZ is right about those guys doing this first, it took this post plus more detailed source code plus developers contacting each other to make actual interop actually happen.

    For my part, I posted information (with source) that's relevant to the peculiar MIDI messaging that you will get out of an instrument that was designed for multi-touch from day 1. It includes a special NRPN that we use to do bends at full pitch resolution from the lowest to highest MIDI note, and pseudocode on problems I find in almost every synth I plug in to. So far, Kontakt4 was like the only thing that seems to really do pitch handling right (but there are efficiency issues in getting it right), Karma does it reasonably well, and almost every single timbre synth is just comically… well… fucking badly wrong; like they never ever envisioned anything other than something with discrete keys and one pitch wheel being plugged into it.

  13. i think as long as you have a situation where you have few (preferably one) apps doing sound rendition, others sending midi, and whatever is in the foreground is not going crazy with non-audio stuff (ie: visuals) that it will be ok performance-wise. midi doesn't stress performance. that's mostly digital signal processing and graphical stuff doing that.

  14. The big manufacturers will never bring out hardware for ios device as they want you to buy there hardware , compatibility midi audio digital etc is the key to sucessful hardware devices this was learnt a long time ago. Software is the same principle as long as midi implementation follows the rules then compatibility with other devices will work. I own a 01v , mpc , nova , nord , drum machines , outboard gear , fx and controllers this all cost me thousands of pounds over the last 15 years , the ipad is the greatest musical tool i have seen in years and will only cost you a tenth of the hardware value .

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