midiGATEs midi probability is an Audio Unit v3 MIDI Effect and CoreMIDI capable app. midiGATEs listens to MIDI input and based on random chance mutes some of the incoming notes to make a busy, repetitive stream of notes a little more interesting and sparser. It has four modes:
Gate Mode - One set percentage to be muted for all notes. Also includes Gate On Repeats (when a note passes through unmuted, also pass through X more notes after) and Gate Off Repeats (when a note does not pass through the gate, also mute the next X notes) to make things a little more interesting.
Note Mode - Each note in the scale (C, C#, D etc) has its own percentage chance to mute incoming notes.
Sequencer Mode - Every eight notes has a different percentage chance to be muted. Can also change the sequence length to be less than eight.
Thru Mode - Nothing is muted, normally not used but there if you need it.
If midiGATEs is inserted as an AUv3 MIDI effect in a supported host such as Audiobus or AUM it should setup and work automatically. If you wish to use it without an Audio Unit host you can toggle the CoreMIDI input and output and use it that way.

What’s New

Version 2.1.0

Changed app name to "midiGATEs probability" to distinguish from my midiFILTr volca apps
Added a time sync option to the sequencer gate, so it can work based on time step (all notes treated the same during that particular 1/8 note step in time) rather than note step (each note treated separately)
Added an animation to show the current active step in sequencer mode
Added a color animation to the current gate type button to show when a note is passed through (white) or muted (black)
Added AU user shared presets
Fixed weird font change
Misc other fixes and improvements

Ratings and Reviews

4.4 out of 5
5 Ratings

5 Ratings

Enrique Raphaël Page Pérez ,

Fantastic, but a little bit buggy!

Lots of crashes on ApeMatrix, and usually in complex project that utilize the AUv3, loading the project after creating it leads to the plugin crashing and unable to reload automatically, forcing you to add another instance manually and reconfigure it. Tedious.

As for the rest? What can I say? This is just magical, I use it a lot in the same way other comments describe. It’s particularly amazing when combined with a sequencer, as it can lead to fantastic “procedural” variation of a loop. Fantastic for drum tracks, but can be used on anything really, especially also for ambience stuff.

Since apparently the dev is focusing on AUv3 support now, I’m sure stability will increase. When it does, i will give this the damned 10 stars it deserves, out of five that is.

Kaiser1313 ,

Great app! Essential for sequencing

Since I bought this app I have used it daily. I usually have five or six instances going in AUM. Works great, no crashes. Perfect for taking complex midi phrases and filtering out notes to make it more sparse and random. This is such important little app, opens up a ton of possibilities.

Leostrong99992222 ,

5 stars!!

Edit sept 2019
Au v3 support added! Get this thing already. Thanks developer!

This app is now vital and indispensable in my workflow. Highly recommend!

To the developer, any plans for making this an Audio Unit (au v3) for use directly with AUM?

App Privacy

The developer, Arthur Kerns, has not provided details about its privacy practices and handling of data to Apple. For more information, see the developer's privacy policy.

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Arthur Kerns
2.5 MB

Requires iOS 11.4 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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