This app puts a multitrack recorder inside almost any music app


MultiTrack Recorder Plugin
This is how we recorded multiple tracks in the olden days, kids.
Photo: Charlie Sorrel/Cult of Mac

4Pockets’ MultiTrack Recorder Plugin is an audio-recording app that can be loaded inside other music apps. If you’ve ever seen an app like GarageBand or Logic in action, you’ll be familiar with the layout of multiple tracks on a horizontal timeline. MultiTrack Recorder Plugin offers exactly that, only it’s designed to be used inside other music apps. Apps that don’t have their own recording functions.

MultiTrack Recorder Plugin

MTR, as I will call it from now on, is an Audio Unit for iOS. Audio Units are plugins that can add functions to other music apps. They often come in the form of effects — reverb, distortion, etc. — or sound generators (like synthesizers and drum machines).

Here’s MultiTrack Recorder running in audio mixing app AUM.
Here’s MultiTrack Recorder running in audio mixing app AUM.
Photo: Cult of Mac

On iOS, a class of apps route audio (and MIDI) between Audio Units, and between other apps. Called host apps, these incredibly flexible apps allow for all kinds of creative setups. But they either offer very basic recording functionality (like essential audio mixing app AUM), or no way to record at all.

That’s where MTR comes in. It adds a familiar, multitrack recorder to any host app.


MTR accepts audio from its host app, and records to one track at a time. It synchronizes with the timing of the host, so you can record — and play back — in time. It offers some basic effects (reverb and delay), but you’re more likely to use specialized AU plugins for that kind of thing.

And here is MultiTrack Recorder Plugin running inside GarageBand LOL.
And here it is running inside GarageBand LOL.
Photo: Cult of Mac

You can then drag and drop these clips around in order to edit them. You also can do some pretty advanced stuff, like time-stretching an imported audio clip to make it fit the rest of the song. (GarageBand on iOS can’t do that.) And, speaking of importing, you can drag and drop any of the clips in and out of the timeline, and also drag and drop from the Files app.

There’s more. Because MTR is an AU plugin, you can run multiple versions, all recording and playing back different things. But the clever part is, they all share the same “audio pool.” That is, all of them record to a shared storage area. This also means that you can drag a recording from one instance of MTR to another.

A brand new way to record music

It’s all pretty wild stuff, and MultiTrack Recorder Plugin even works on the iPhone. Well, mostly. Members of the AudioBus forum, the biggest and best iOS music app forum around, report difficulty using some of the advanced editing features on the iPhone’s small screen. I’ve not had any problems yet, despite my dodgy iPad.

4Pockets’ MultiTrack Recorder Plugin changes how you can make music on the iPad. Now there’s no need to try to route all your other music apps into something like GarageBand (which is extremely clunky when it comes to Audio Units and other sharing mechanisms). You can bring the recorder to your music apps instead. It’s a pretty radical reimagining of computer music making, and I dig it.

MultiTrack Recorder Plugin

Price: $9.99

Download: MultiTrack Recorder Plugin from the App Store (iOS)


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