Tutorial – Ableton audio feedback part 1

Introduction

This tutorial is the first in a series covering feedback in synthesis and production, and how it can be a fun way to create new and interesting sounds with a seeming life of their own. Exploring feedback techniques can bring a complexity and uniqueness of sound to your tone palette, it is a sound with internal coherence so it might appear more “natural” than other types of synthesis or effect.   If you are the type who learns by dismantling a working example, then there is a downloadable example file at the end of this tutorial.

What can I make with feedback?

The types of outcomes you can create with feedback range from Dub style delays, to no-mixer synthesis, to looping evolving ambient soundscapes.
here are three audio examples  of the sound of feedback

Dub delay

Regenerative looping

A no-input mixer

In this first tutorial I will focus creating the Dub Delay and a little bit of regenerative Looping. The tutorial also shows you the basics which can be used in all of these cases, this involves activating feedback in Ableton Live’s effect return channels and showing you how to progressively reshape the sound produced until you have a unique effect.  I’ll explain some pitfalls to avoid which we should bear in mind as our experiments become more complex.  In later tutorials I will cover feedback matrices and automation, intermodulation and other more advanced topics.


A “Dub Delay”

A short history and explanation

In the recordings of Lee “scratch” Perry, King Tubby, and others, there is a very recognisable echo sound which has come to be recognised as the “Dub Delay”. Often the effect device used was a very simple type of analog echo device known as a bucket brigade delay, however the notable sonic features which made the distinctive dub sound was NOT inherent in the delay device itself but in the way it was routed. This is what we will recreate.

Traditionally the way to incorporate effects returns on an analogue mixing board would be to have a send dial on each track (such as Drums), the effect send dial would send a percentage of the track signal out to the delay device, the effected signal would return back into the mixing board onto a dedicated return channel. This return channel was a very simple channel with no EQ, or any other features common to the rest of the mixing board tracks. The return channel could not send to other effects.

What Lee Perry (and others) did was to route the effect output of the Delay unit into a normal track channel, thus allowing the effected Delay returns to be EQed and even sent back to themselves using the effect sends, delay-eq-delay-eq-delay-eq-….   . Additionally it meant that the mixing engineers could now send delay into reverb, or reverb into a flanger and then into the delay.  This allowed the creation of very flexible feedback loops which could quickly get out of control and start making chaotic noises, but a skilled operator could manage this chaos into art.

For some examples of Dub Delay in songs you can listen to a few in the dub section of my music shop

This is precisely what we intend to recreate.


Step one – make a feedback channel

Activate Ableton’s feedback mode

enable feedback ableton liveIn Ableton Live we have a (possibly) unique ability to allow return channels to send back to themselves and each other, but by default you will notice that the return channel send dials are deactivated, this is to prevent users encountering unavoidable issues. We need to activate the return channel send dials for our experiment to work.  Create a new return channel and title it “dub delay”, in that new channel right click on the send dial which would send back to itself and choose “activate send” from the context menu.

One thing you should understand is that by allowing Ableton Live to send effects back to themselves we have chosen to make plugin latency calculation for this special track almost impossible, so Live will no longer do PDC on tracks with feedback activated. I will explain further in the section titled “warnings”

The basic effects

Now find the “simple delay” device and drop it into this track, turn the wet/dry on the effect to 100% wet and VERY IMPORTANTLY turn the feedback down to zero. The reason for that is we are going to take care of the feedback signal path, we are taking that away the effect.   Set the left and right sides to the same speed.

In a normal delay effect device path the audio comes in and this input gets sent to a “buffer” where it is delayed for a specified amount of time and then this wet signal is mixed into the dry signal and output. The feedback control sends an amount of the delayed signal back into the input so that is delayed once again, and that mix appears at the output and again is sent back to the input.

feedback-delay-path-a

That closed loop is no use to us if we want to take control of feedback tonality. We need to inject our own toys into the loop so we have much more shaping control over the outcome.

You will need a sound source as we proceed, and I recommend any kind of snare-drum.  Load a snare into any channel and use the effect send dial on that channel to send to your “dub delay”

Read more …

Tutorial : generative music in Ableton Live

Generative music in Live

Here is a brief tutorial on making generative music with Live. This tutorial first appeared on the Ableton Live Forum, in 2007 – so the examples were made using Live 6.07  and will work with any version of live later than that.

What is generative music?

Generative music is where you provide logical or programmatic ‘seeds’ and the computer grows you some music based on the parameters you set out, Brian Eno is probably the most famous practitioner.

Feeling lazy?

Here is a LivePack to download with four examples of varying complexity.

Download the Live Pack

Why make generative music, or get Live to make music for you?

Generative music is a different beast from making a track of your own, it is more like planting a garden. In fact a generative piece is like a glorified wind chime, so we could equally ask ourselves “why do people have wind chimes rather than stand in the garden hitting aluminium themselves?”  The answer would be the same – the sounds which result may not be “music” but they can be good background noise and in that way quite beautiful and surprisingly interesting as ambience, furthermore the underlying generation can be tinkered with to deliver a wide range of what appears to be expression. A generative piece will sustain a low level of interest for hours!

Live is quite a good environment for creating generative music and I have two methods to do so, an audio based method and a midi method.

I will focus on the more midi-oriented method here.
There are limitations to how far you can go with Live and generative music, but what you can achieve is entertaining.

How it is achieved in Live

To make generative music we need to make Live play or do something whenever a condition is met, we get flexibility by giving the program some freedom. Instead of saying “EVERY time a bar starts play a C minor chord”, we want variation. An example might be “Sometimes play a chord (from a selection of chords) on either the first or third beat, and if you do then perhaps play one of these ralated chords after it, or perhaps think about playing this tune instead”

So now we have a random event which is constrained by a limited set of outcomes, it sounds passably like music.

Tools of the trade

Midi Devices

  • Random – to generate random pitches
  • Scale – to make those pitches be less random
  • Velocity – to make random note start triggers
  • Pitch – to transpose phrases chords and notes
  • Note Length – to give variation to the note length
  • Chord – a variety of uses

Audio Devices

  • AutoPanner – can be used for ‘cross-fading’ between one component and another
  • AutoFilter – similar but different
  • BeatRepeat – repeating random stuff makes it sound like you meant it!

obviously the other Live devices such as Reverb get used, but the above are the ones that are strictly ‘generative’

Getting started – ‘plinky plonk world’

Lets make a bad start!  Drop a Midi instrument on a track so you can hear what is happening during the exploration process, use a simple patch like an electric piano (or a Simpler with a triangle wave in) and give it a long release. At the start the output will sound pretty dull, trust me it gets better.

we need a timing pulse to begin with, I use a single midi C3 note in a session clip, I loop this on a quarter bar.
This gives me a nice regular trigger at a 120bpm for the random events to take their cue from. Like this …

midi

That’s all the midi programming we will need done!   Next we need to make that ‘trigger’ random, to do this we use the Velocity device. Actually two velocity devices, like this

Generative conditional if-gate

The first takes the incoming repetitive note and randomizes the velocity.
The second one only lets notes through which fall in the selected velocity range.

This is the core concept of how we will select and filter random values in Live. How we can decide “do I do something, or not?”

In the image that range is from 0 to 59. You will see that I assign the range to a macro called ‘chance’. Try this, it will soon become apparent what ‘chance’ does.
Remember to set the Velocity device to ‘gate’ mode.

You might notice I also set the ‘random’ high on the second Velocity – this is so that further down the chain I have a ready made scattering of random values to make use of for further filtering (you’ll see!)

Now we need to make the pitches change, the most brutal way is to use the Random Device, simply dropping it in the rack after the Velocity section will give you an annoying random ‘tune’.

Give it some pattern with the use of the Scale plugin, choose a nice preset or set your own if you know how … and there you have your first very basic generative thing. A bit shit though isn’t it. It plays random notes, they have random pitches which conform in a brutal way to a scale. It’s a start. It’s hardly music though.

Generative music if-gate repitching

Make it sound more interesting

There are a few things about our example above which make it a bit dull, unpleasant and it just .. well, un-interesting. It sounds very machine like in its random nature rather than musical, there is no tonal variance such as there might be in a human musical peice, there is no sense of drama, no sense of space or *cough* ambience. If we can simulate any of that, it would help.

Conditions of Interest

We used the velocity devices to set a ‘condition’, if the value is within a certain range the note sounds. We can expand this to become what programmers know as an ‘if – else’ conditional.

Generative conditional-if-else

Here we set two ranges, one produces one outcome, the other will produce another outcome.
This can help us get some drama and tonal variance in there, for example: by allowing any (random) value between 60 and 70 to trigger one chord, while anything between 70 and 80 might trigger a different chord.

Those are ‘conditions’ , when a condition is met an action is taken. To a programmer this might read as if (var>60 && var<70) { do this } else if(var>70 && var<80) {do that}

We can make our piece more interesting by cascading the variations, or to put it in English ” if the value is between 60 and seventy then do either this chord or that chord, if you do that chord then consider these further three variations”

A second choice of conditions follows the first, cunning use of these cascades provides potentially musical output.

Cascading The Variations .

You saw how I set a ‘condition’ with two Velocity plugins, and how we can set two different outcomes using ‘if – else’. Now imagine dividing the random values up into many zones, this way you can create little themic areas.
You can start to go further down the fractal tree, each conditional zone can have a new random value generated to make new notes for itself. Each ‘conditional zone’ can be a different part of your song. The ‘riff’ , the ‘bassline’ , the ‘chords’ . Each of them can watch a zone and do some more complicated ‘riff’ or ‘chord’ related actions anytime that rack is triggered by the main condition.

Here we have the zones of a random seed divided into themes

Generative branches

and in this example the watched zones are further divided to play notes of a riff, each riff note is also conditional. The cascade effect first decides if a note should play on a particular beat and then it decides which note from its small pallet of notes. Out of view here, a further conditional decides whether to transpose the eventual riff.

riff

This is making my brain hurt!

Although this sounds very technical, in fact (if you are anything like me) you will simply set up a few conditions and then add stuff where it seems right, until it makes a nice noise. Once you have an idea of the basic principles you can simply sculpt or garden yourself a tune in an ad-hoc manner. You will notice that my example files aren’t exactly exemplary of order and fore-thought.
But it certainly helps to have some kind of plan!

I think that’s enough to absorb for now.
So, here are some example files

Examples

  • Zawinul – a complex peice which should sustain a lengthy listen
  • Harpist – an example of riffs riffing away
  • Experimentaloid – a more simple example
  • Infinity Plus one – more of the same.

Download the Live Pack

This is Your Theme

something I’ve been working on, a kind of 1970’s cop show vibe, funky and dirty with a lumpy 7/8 groove behind it.

 

 

Welcome

Hi and welcome to the site of Steve Angstrom, it’s the place to listen my music if for some reason iTunes and Amazon’s 30 seconds is simply not good enough!   This site also contains a shop where you can buy my stuff, and at bargain prices I’m sure we all agree.

There’s plenty more to come, but for now feel free to meander around, listen, and enjoy.

A new track called Phases

Here’s something I’ve been working on recently, it’s called “Phases” and it’s centered around a lapsteel and pulsating bass with a laid back beat underneath it.  It’s one of my favourite things I’ve done for a while.

I’ve been told that it’s evocative of cruising in slow motion through a hot rocky desert, well see if you agree on that – and hopefully you like it.

Here’s a preview, it’s of course available in the store right now. Or via the ‘add to cart’ button below

Read more …