Free App, Music IO, Lets You Route MIDI Over USB On iOS & Mac

music-ioSecret Base Design has released Music IO: MIDI over USB – a free app that lets you route MIDI via USB between iOS & Mac.

This is the MIDI-only version of Music IO, a MIDI and audio-over-USB solution for iOS. It’s fully bidirectional and near-zero latency.

This version of the app is free for a limited time.


  • Send & Receive MIDI between any CoreMIDI apps over USB (Lightning or 30 pin) with no perceptible latency nor jitter
  • Large sysex messages (eg. bulk dumps) handled seamlessly
  • Choose “send to” ports (OSX and iOS)
  • Choose “receive from” (OSX): route MIDI from anywhere to your iOS device
  • BridgeClock, a ground-breaking inter-device MIDI-clock-synchronization technology, provides jitter-free sync between platforms

Here’s a video demo:

Note that the video demonstrates the paid version, which supports streaming both MIDI and audio.


Music IO is designed to work with iOS 7 or newer, and OS X 10.7 or newer. Audio is transferred in 32-bit stereo, at 44.1khz. A companion app for the Mac is required – it’s a free download.

11 thoughts on “Free App, Music IO, Lets You Route MIDI Over USB On iOS & Mac

    1. Yes — that’s right. We’re streaming audio directly into the VST and AU plug-ins (and audio streams out too — that’s how the effects loop stuff works). We’re trying to side-step the aggregate device hassle, and get multiple channels of audio going in and out. It’s a bit of a different work flow (there’s some bouncing of tracks to get recording to work nicely), but I think it’s a productivity win.

      And I should note — the app is a joint effort between my group, Confusionist Studios (MIDI Designer), and Audeonic Apps (MIDI Bridge). We’re pooling our expertise to try to make the app as versatile and robust as possible. Good fun, and good people to work with.

      1. Cool app, but how does it compare to and different from MIDI/audiomux apps? Since I already have those? Thanks.

  1. Even though I already bought the full audio/MIDI version, I decided to pick this up while it is free.

    I’m not sure if it has any lower latency than the full version, but I just thought it made sense to grab it, as there will be times I’ll use MIDI only for one thing or another.

  2. Thanks for the coverage! There’s no need for the free MIDI version, if you’ve already got the combined audio and MIDI app; they both use the same back-end server on the Mac. The release of this app is timed with the combined version update (that has four stereo tracks of audio from Mac to iOS and back, as an effects loop setup — with VST and AU plug-ins, for all the folks here on Synthtopia who were clamoring for them!).

    Unfortunately, no support for modular. I’ve looked into using the headphone jack of an iOS device as part of a CV analog system. It’s do-able, but my guess is that there would be three people on the planet who might use it, and they would be immediately shunned by everyone around them.

  3. Patrick –
    The headphone jack… do you mean that the two outputs (L/R) are DC coupled?
    If so, I can think of lots of possibilities to connect them to modular devices..

    eg. Two sides as CV. One side as a CV and the other as a gate.

    There is at least one app that I can think of that seems to be quite popular among modular enthusiasts = CVToolkit.

  4. I just found out about this app and it’s solving a lot of problems for me.
    If I add a camera connection kit, will I be able to send/receive MIDI to Ableton with Music IO AND trigger IOS synths with a USB controller? Can I do both?

  5. Will this do SYSEX Transfers? This would be in reference to Yamaha DX7 Synth’s for loading sounds. People have libraries for MAC but not for iOS. I have a IPad Air 2 that I want to control my music with. Let me know. Thanks

Leave a Reply