Concentric Rhythm 4+

Jeff Holtzkener

Designed for iPad

    • 4.6 • 41 Ratings
    • $3.99
    • Offers In-App Purchases



Concentric Rhythm is an interactive tool for generating, developing, and exploring musical patterns. It uses geometric transformations and many other simple processes to create, develop, and evolve music.

The looping musical timeline is visualized as a circle, which allows you to treat musical patterns as concentric shapes. This makes performing geometric transformations such as rotations, reflections and folding very natural and intuitive.
It also provides tools for melodic lines such as random-walk generation and scale-based inversion and transposition.
You can generate rhythmic lines using cross-rhythms or the Euclidean algorithm, and allows for great visualisations of complex polyrhythms.

Concentric Rhythm now allows you to assign each pattern to a different MIDI channel and send your results to other MIDI compatible apps or devices.

Concentric Rhythm was originally developed as a new way to improvise electronic music, but it is also a great tool experimenting with and developing musical material, or just for casually playing with music in a unique, hands-on, way.

Many of the ideas here were inspired by the book ‘The Geometry of Musical Rhythm’ and this app is a powerful tool for anyone who is interested in exploring these ideas. But at the same time is easy enough to use that anyone (even with no musical or mathematical background) can make interesting musical patterns and think about the musical world a little differently.

Note: There are known compatibility issues when used with AUM, especially on iOS 14

What’s New

Version 3.0.4

- can auto-save last MIDI Send value
- significant improvements for Audiobus and AUM hosting

Ratings and Reviews

4.6 out of 5
41 Ratings

41 Ratings

Matreve ,

About perfect.

I tried, but so far can’t find anything negative about this app. About as good as it gets as is!

It is probably mathematically possible with all the transformations, but surprisingly I did not find an easy way of converting say a 6 note rhythm into 5 or 7 note one while keeping even distribution of notes around the circle.

An “unwrap” feature could be handy, basically allowing user to convert the sequence into a more traditional rows/columns sequencer patterns (can be done by exporting MIDI into any piano roll type DAW but in app functionality would be useful).

I also wish that turning the rings in relation to the other ones was not quantized and allowed in-between positions, this could create even more interesting rhythms.

And if it was possible to divide any distance between two notes into subdivisions and create notes there...

Once again, this app is about perfect and all above is just a fantasy...

Edit: Not sure if this is a feature meant to prevent recording of IAA into an AB3 in the free version, but as soon as the AB3 is opened the app changes the sound into an echoey one and even after quitting AB3 the sound remains changed (comes back to normal if you quit the app and reload the project). IAA can be recorded in AUM without trouble which tells me the changing sound is a bug .

tgreenough ,


This app is truly a life saver. I’m a pianist specializing in contemporary music, and I was searching for an app that I could program some of the polyrhythms that I’ve been encountering in my repertoire. I love that I can program something like 11:13, but I’m even more blown away that I can adjust it to account for dotted rhythms and rests. Ive been sharing this with practically all of my friends and colleagues in the field. Thank you Jeff for creating this!

michaeljjay ,

Paying for midi outputs?

Well Jeff, that post was 6 months ago? I wish I could show everyone the screenshot that I have with me. It says “Enable MIDI?
Sending midi to other application/Devices is available as an in-app purchase ($4.99). If you would like to enable sending midi, select ‘Purchase Send MIDI’’. If you have reinstalled Concentric Rhythm and need to restore the purchase, select Restore Send MIDI’.
It showed 6 months ago on 1 option. 1: Purchase Send Midi.
After checking back 6 months later, it now shows 2 options.
1: Purchase send Midi.
2: Restore Send Midi.

There was no restore send midi option when that post was made but if you were concerned about what people were saying, maybe you should pay close attention to your customers and ratings.
I’ve updated my rating to 4.

I had a conversation with this guy about making this app with 16 midi outputs a few months ago, even sent him some concepts. That’s when I paid for this app and midi outputs was part of the purchase. Now it still doesn’t even have 16 midi outputs and he’s charging people to use 1 midi output?


Developer Response ,

This is somewhat misleading. The MIDI IAP lets you send each ring to a different MIDI channel. You can use up to 9 rings, so you can send to 9 different channels simultaneously (but you can assign each ring to any 9 of the 16 channels). I don't understand what you mean when you say I am 'charging people to use 1 midi output'? There are as many outputs as there are rings - and there are 9 rings. Most people don't even use all 9.

Anyway, I do appreciate that you took the time to email me an alternative layout idea for the UI - but after consideration, I decided not to implement it. I found that adding more rings to the screen made the app more difficult to use. I love it that people send me their ideas for the app - but not all ideas are workable.

App Privacy

The developer, Jeff Holtzkener, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Linked to You

The following data may be collected but it is not linked to your identity:

  • Usage Data
  • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More

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