Saturday 27 July 2019

Several M4L variations on Random for controlling parameters in Ableton Live

I am my own worst enemy. I find it difficult to resist making comments on some Facebook posts, and I find it hard to not create MaxForLive devices when there isn't one available as part of the comment.

Which is where MIDIrandomA comes from. Andxre Andre posted in the 'Max For Live Users' group that it seemed like:

'...the max for live essentials LFO... feels like it always gets to the same values a lot'.  

 And I commented:

Random’ is a difficult topic. People have a number of expectations that do not necessarily match to a true random source. There have been published papers describing the differences between a true random source and what people perceive/expect. People seem to expect no repeated/similar values, no small differences between successive values, and no repeated similar sequences, and more... Some ‘random’ sources are actually processed so that they fit better with expectations - Apple’s iTunes playlist generation and shuffle, for example. 

And I kind of committed myself to making a less random 'random generator'...


MIDIrandomA is the result. It isn't perfect (the repeated sequences' bit isn't included yet...), but it does provide 'constrained' random values that can have the sort of characteristics that Andxre Andre is looking for. As always with my rapid development devices, there's probably a lot that can be improved, so feel free to let me know what you think.

MIDIrandomA is a random 'control voltage'/number/value source. It has three different types of random noise, instead of the more usual single source, and so provides comprehensive control for exacting requirements.

Type A has four rotary controls, and provides detailed control over the gain, the quantisation, the smoothing (logarithmic accumulation), and the thinning (non-linear amplification).

Type B is the classical 'Random Walk' and only provides control over the maximum size of the step between one output and the next.

Type C is the opposite of B - no repeated adjacent values are allowed, and the delta size (difference between successive output values) is the minimum that is allowed.

The generation of random number values (0-127) can be triggered by a free-running LFO (Rate, =Not Synced=), or one of several MIDI note or velocity triggers, which work from notes on a piano-roll Clip in the same track.

The output can be mapped to any co-operating control in Ableton Live.

Getting MIDIrandomA 0v01

You can get MIDIrandomA on

Here are the instructions for what to do with the .amxd file that you download from

(In Live 10, you can also just double-click on the .amxd file, but this puts the device in the same folder as all of the factory devices...)

Oh, yes, and sometimes last-minute fixes do get added, which is why sometimes the blog post is behind the version number of

Modular Equivalents

In terms of basic modular equivalents, then MIDIrandomA 0v01 would probably require three different npise/random generators, plus some post-processing (non-linear amplifier, filter/accumulator, not sure about the repeated value removal...) to give the same sort of functionality, plus a little bit of switching to do the 'Type' selection and the sync options, giving a total of about  10 ME.


There's now a three output version of this, called MIDIrandomABCmr02. You can learn more about it here:

And here's a link to click on if you find my writing informative:


  1. awesome stuff i been looking for a Sample & Hold sort of function that randoms a mapped vile every time a note plays. this seem to be the answer!

    One good thing about Ableton's default LFO tough is that you can make it to many parameters with different ranges..

    For devices that don't have that functionality built in we can use "MultiMap" from Ableton Live Essentials anyway!

    Thank You!

  2. Which sets me thinking about a variant...