Morphing into a loop (Was: Re: slider for a vortex)

[John Pollock <johnpollock@delphi.com>]

In a previous post, I mentioned morphing into a loop, and Michael
Preston wrote via private mail:

>I bet the whole loopin' crew would like to read about the Vortex 
>parameterization for morphing into a loop. I haven't found that special 
>morphing pattern yet. I'll be looking for it.

Look no further than Deja Vu A and B.  Select B, set Envelope to 1. 
That's it!  (I was misremembering that it was more complicated than
that.)

A description of how I use this trick may be instructive... or it may be
boring, but here it is anyway: ;-)

There's this Thing I Play in two sections, fingerstyle, at a medium
tempo (the only one I know), with a Latin feel (accents on the first,
fourth and seventh eighth-notes).  I've been trying to find a way to
make it into music (as opposed to just a pleasant-sounding Thing I Play)
for years.  It's in the key of A.  The first section is basically three
chords, though they're all extended or altered, in what amounts to a
24-bar blues format; the second section is essentially an etude I worked
out to drive the sound of m7b5 chords into my head (worked very nicely,
too.)

The first section sounds OK by itself, _once_, so I play it with the
Vortex in Deja Vu B.  With Envelope set to 1, input to the delay line(s)
is cut off, so the guitar sound comes out dry.  I tap the tempo in-- a
full measure.

At the beginning of section B, I tap the A/B switch, bringing in those
delightful ducked echoes (something I'd never experienced before the
Vortex), which combine with my playing to make a melody that was never
there before.

The last measure of the second section is a V chord.  I tap the A/B
switch on the downbeat, and play just three notes:  E dotted quarter
note, F# dotted quarter note, and a muted string slap.

What the Vortex gives me in return is much more complex.  There are one
or more sounds on just about every eighth note in the loop, with
percussion from the string slap audible on the fourth and prominent on
the seventh.  There's a stacatto A bass note on the down beat, in
addition to both the E and F#.  And the doubled or alternating E and F#
combine very nicely to my ear with all of the following chords.  "My
playing, but more of it"--Yes!

Obviously, the Morph parameter values are the foundation of this
process.  Since Deja Vu B accepts no input with Envelope set to 1, what
goes into the loop can only be what goes into the Vortex during the
morph, plus what's carried over as echoes from notes played right before
the morph.  Preset Morph value for both A and B is 21.  Tweaking either
or both could significantly alter the nature of the loop.

Another obvious avenue for exploration is morphing into Deja Vu B from
a more prominently effected patch, especially one with modulation
occurring before the echoes, _especially_ if the echoes are
polyrhythmic... :-) :-)

Of course, with an expression pedal assigned to Envelope in Deja Vu B,
the loop can be added to after creating it in this fashion.

I suspect I'll be laboring in this particular trench for quite a while,
since the Vortex is my only looping device (still haven't heard whether
I'm a winner in the GC JamBro lottery).  
-- 
John Pollock
mailto:johnpollock@delphi.com
http://people.delphi.com/johnpollock (Troubador Tech)