Generative Music - Part 2


This post follows on from Generative Music - Part 1: Generative Bass, the goal of which was to create a random bassline using various MIDI effects available in Ableton Live. If you haven’t already, it’s worth heading over there first before continuing as it describes the method in more detail which isn’t covered again here.

In Generative Music - Part 2, we’ll be creating a Live set that produces a randomly generated piece of music with multiple tracks.


Steve Angstrom’s original post on the Ableton Forums was way back in 2007, using Ableton 6.07. Since then he has reposted it, together with a Live pack which contains some great instruments he created from triangle waves and white noise samples. It’s worth checking out the Live pack from his site to get some insight into how he created the sounds which, in themselves are impressive.

These concepts have been extended by a tutorial from SonicState which I would also highly recommend. It takes a slightly different approach in how the instruments are organised, which allows you to control the randomness for each individual track.


Please refer to Generative Music - Part 1: Generative Bass for more details on all the devices used. Links to the Ableton Live manual on each of the devices are also on this page should you want a refresher.


The way the MIDI rack has been created is very similar to the one in the previous tutorial, although there are some differences in my approach this time around to make life a little easier.

This Live set was going to include more than just one track, so to save time I created a Generate MIDI Effect Rack in my user library. This way I could drop it on each track without creating it again each time:

Fig 1. Save your Generative MIDI Effect Rack

Fig 1. Save your Generative MIDI Effect Rack

Once I had dropped them on the track, the branches for each track’s instrument were tweaked slightly. Velocity Lottery is set to use Gate mode. Notes are removed if they fall outside of the range. If a note falls within that range it will be played. The same applies to the Velocity device on each of the Branches in the 2nd midi rack, only notes which fall within the range of the Velocity devices on that branch would be played.

For example, on the Gen MIDI Effect Rack Bass I use Note Length on a few of the branches as I’d like some bass notes to occasionally hold for longer:

Fig 2. Gen MIDI Effect Rack Bass

Fig 2. Gen MIDI Effect Rack Bass

However, on the Gen MIDI Effect Rack Lead, I used an Arpeggiator on some of the branches as I would like to have different arpeggios play if that branch happens to be triggered ( be careful not to overlap the ranges of the Velocity device in any of the branches or you’ll hear multiple arpeggios playing at the same time ):

Fig 3. Gen MIDI Effect Rack Lead

Fig 3. Gen MIDI Effect Rack Lead

Also, notice the range of the Velocity Lottery has been mapped to ‘chance’ parameter on ‘Velocity Lottery’ and to add a further element of chance by adjusting the values in clip view automation:

Fig 4. Generative MIDI Clip View Automation

Fig 4. Generative MIDI Clip View Automation

Workflow Tips


Save the generative MIDI racks you create to your library so you can drop them in quickly. They can take a little while to set up so it will improve your workflow at the initial creation stage. If you’re looking for ways to improve your workflow, check out Animus Invidious’ ‘How to Organize User Plugin Presets Like A Boss In Ableton 9 Using The Hidden Architecture’.

With this many racks and devices, it is important to name everything clearly. It can become confusing otherwise.


As opposed to writing a regular track with a more traditional song structure, it’s not immediately obvious when its finished - as if it isn’t difficult enough finishing something!

However, I did find that once a generative piece begins to induce you into a kind of hypnotic trance, you know then, that it is done!

What Next

The Live Pack that accompanies this tutorial is available below in the Article References. Download it and open in Ableton Live to deconstruct the tracks. Apart from the Beats, all tracks follow the same pattern in the device view, beginning with the MIDI Rack followed by an Instrument Rack and Effect Rack:

Fig 5. Device View

Fig 5. Device View

The drums track was something quickly put together using Operator to keep the piece ticking over.

Although the Live Pack download is available, I would recommend building a Generative MIDI Effect Rack from scratch. It really helped my understanding of how Steve Angstrom and Sonic State achieved what they did.

The longer I spent doing this, I came to realise that the type of samples you are using and sounds you create will guide you towards the most appropriate MIDI effects, so:

  • The track on which I used a found sound really lent itself to arpeggios.

  • Adding the Note Length to the bass notes seemed to work well too.

  • I used some samples from Steve Angstroms original Live Pack ( thanks again Steve! ). After tweaking them a little, they led me to chose the Hirajōshi scale - it just seemed to fit the sound and movement of the track.

Have a go and before long, you’ll soon be coming up with your own ideas and produce something unique to you.

To the right you’ll find what fell out of Ableton for me after a few nights.

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