Laptop live-looping in Numerology

[Per Boysen <per@boysen.se>]

Hi list,

I'm pasting in this discussion from the Numerology list, if someone 
here is interested in laptop set-ups for audio live-looping. I also 
tried Live 4 but actually found Numerology to fit my needs better. Many 
of the features described below in the "long version" was simply not 
possible to achieve in Live, or they came with too disturbing side 
effects.

For ages I have been longing for a "meta instrument" that would let me 
record and manipulate many loops at the same time. Thanks to the new 
audio functionality of Numerology (for OS X) I have managed to achieve 
this. To begin with only in a rudimentary form, but now when the system 
is defined it can grow and improve.

First, here's a short demo sound clip of plugging a guitar into the 
powerbook and tap dancing over the FCB1010:
http://www.looproom.com/audio/Numerology_Augustus_Looping.mp3


Short version:

> It's basically three instances of the AU plug-in Augustus Loop,
> transposed and manipulated in real-time from a Behringer FCB midi foot
> pedal. Twelve Numerology Group pre-sets bring the looping set-up into
> different "modes" for certain tasks or for instant transposing of all
> loops to match chord/key changes. A number of control sequencers run
> the filter cut-off built into the looping plug-ins. Midi expression
> pedals can change Gate Division of those cut-off sequencers while the
> thing is making noise.



Long version:

Theoretically it's about four main functions.

1) Running multiple audio loops (here three simultaneous loops) and
being able to overdub audio input by using midi foot pedals.
2) Changing the length, or direction, of loops while they are spinning
(creating poly rhythm).
3) Globally groove quantized "dynamic gating" of each individual loops
output. Changing the "beat sync" while loops are spinning (here done by
Clock Division of the sequencers that control each loops filter
cut-off).
4) Transforming pitch of ALL LOOPS by just ONE COMMAND (midi foot
pedal). Pre-sets of loop pitch transformations that match most
chords/keys (here done by Group Preset)

I chose the plug-in Augustus Loop because that's the only AU I know
that has a "hold" function, in Augustus called "Freeze Loop". The
Lexicon PSP 42 would also do fine, but it's not available as AU and it
does not have a Reverse Loop function. Typically both plug-ins were not
originally designed for live looping, rather as a "tape delay
emulation". That's the background to the "tape scratch" sound of
Augustus every time you mess with the virtual tape. This can be a bit
annoying when you run many simultaneous loops and change their pitch
all at the same time. I hope developer OS will make this cool sound an
option in future versions of Augustus Loop (don't take it away, please!
Just make it optional).

Now for the audio part:
Playing the instrument on the Numerology "audio input", running three 
looping
plug-ins in groups/channels set to Aux 1, 2 and 3 as the audio input.
Also an Apple Matrix reverb in one group with Aux 4 as input. External
audio input channel sending all aux's to distribute audio into the
loopers and the reverb. The three loopers also sending aux 4 to reverb.
A fifth Group/channel has an iDrum plug-in. The direct input, the three
looping channels and the iDrum all have one compressor each, Neodynium
by Elemental Audio Systems.

Drumming:
As this is the pilot set-up I have not bothered to create drum
sequences in Numerology. Since I have now seen that it's all working 
fine, that will come next. There will be four sequencers with the 
option
to manipulate the Clock Division, individually for each drum
sound/sequence. Manipulation carried out either by Num's Dual LFO or 
from midi expression pedals.
Maybe I will find good use for the Triple X Glide function here? As for
now I just put the iDrum there and had a Dual LFO scroll through four
different drum patterns - iDrums own patterns that is.

Used control modules:
I'll just go through them on a row. A great part of the hard work was
to find ways to program the midi foot pedal board (Behringer FCB1010),
but that's another story.

Three "1010 Control Sequencer". Together with three "393 Parameter
Modulation" units these sequencers handle the dynamic beat synced
gating of each loopers filter cut-off. All three sequencers are set
differently, like an "Elvin Jones type drummer"; never all of them
hitting a punch together but rather leaving out space for each other to
fit into a polyrhythmic groove. Clock division of each "dynamic gating
sequencer" addressed by a midi expression pedal. Different pedal modes
to get at the three loops' Clock Division one by one. For each pedal
mode the second expression pedal is getting lined up to the Glide
function of the Triple X that catches the midi cc input from the pedal.
This means I can both manipulate groove and attack of the filter
"slam". (The way to catch the midi cc input for the Glide is to use a
Midi Input module and then in a Param Mod directing the Inputs cc A, cc
B, and cc C to the "Glide box" targeted (No AutoScale in Param Mod used
here).

Now we're at the last function: transformation of pitches to match
chord/key changes. Here I'm using a "141 Four Track Combo Sequencer"
and addressing Loop Pitch of Augustus Loop by three "3939 Parameter
Modulation" modules. The technique is to set the pitch for the three
loops in the Four Track Combo Sequencer and save it as a Group Pre-set.
Then set up the next combination of loop pitches and save that as
another pre-set etc etc. I have ten different pre-sets for ten
chords/keys to use when improvising music. Some of the chords change
octave in the middle of the 16 step pattern, but only where it sounds
good according to how much audio is being pitched for that particular
chord and that particular loop (there are three loops in harmony, you
know). Although the key changes for each pre-set the loops keep their
typical arrangement: Loop 1 for bass (down one or two octaves), loop 2
as close as possible to the pitch it was recorded in and finally loop 3
one or two octaves high. I have a certain mode (two dedicated pre-sets)
for recording audio into the loops. In recording mode the loops are not
transposed. The same foot pedal that stops recording into one loop also
transposes that loop to its working octave, when going out of recording
mode. So when I need to play some notes into the bass loop I have to
lift it up to the mid octave for a second. When I have punched in a
note or two the loop dives down to the bass octave with that funny
"tape hiss scratchy swirly" sound. A trick also possible, thanks to
this arrangement, is to record into all three loops at once and then
with just one press of a foot pedal freeze the three loops and
distribute pitches to bass, mid and high.

Other Augustus Loop parameters controlled from the FCB1010 by
Numerology's Triple X and Parameter Modulation are:

- Loop feedback
- Freeze Loop (the "recording mode" referred to above)
- Reverse Loop
- Triplet

I may also in the future make some pedal buttons address "Beat Devisor"
of Augustus Loop. This goes from 1/1 to 1/32 and gives some funny and
unpredictable result when changed while audio is looping. (maybe OS can
predict what's happening there but I'm happy not understanding it
completely - it just sounds cool ;-)

I think that's all. This run-through is also a good back-up for me if I
should loose the Numerology documents that hold this set-up.

cheers

per