AW: AW: DJ techniques in live looping (Re: video on loop turntablism) - also for Jeff Larson!

["Rainer Thelonius Balthasar Straschill" <rs@moinlabs.de>]

Jeff, 

you said:
> I don't pay much attention to the DJ world, but if I 
> understand correctly scratching is a combination of playback 
> direction changes with continuously variable rate shift.

and continue to state:
> This might sound similar to turntable scratching but I doubt 
> it would feel the same.  We would probably need to experiment 

(To avoid any confusion: I won't talk about other DJ techniques in this
discussion, like beat-aligning two turntables. This is beyond the scope
here)
First of all, looking at scratch DJs, the turntable or disc without any 
hand
interaction is not at rest; the motor of the turntable is always (?) on.
Then, while the description you suggest of signed playback speed is not 
what
the DJ actually controls. With the exception of some specific maneuvers 
(see
below for backspin), the DJ's fingers stay in contact with the vinyl, so
what he controls is the differential sample position relative to the sample
position at the time when he put his hand on the record. And he only
controls that over a relatively narrow range.

On exception is the backspin maneuver, where he gives the record a spin in
reverse, resulting in some fast, reverse playback, which would gradually
move back to normal playback, but is normally ended when the reverse speed
is still very high by quickly tapping the record and thus returning to
normal playback. Thus, I don't believe we would need to model the
intertia/drag effects here.

In between scratches, however, he will control sample position
differentially or absolutely in a wider range, either by turning the record
around in either direction, or by placing the stylus onto a different
groove. But let's just ignore that here...

> Crossfade that you mentioned would be much simpler, just make 
I believe, here we could either go with a button-controller susMute or, if
that sounds bad, with a button-controlled very fast volume fade.


The problem I see here is that this may be tricky for Mobius to have
playback be controlled by sample position values, rather than by the usual
transport concept. Can this be done?

        Rainer

ps: If you have the time, you might want to go to a music store and see how
e.g. Kaoss Pads implement this. With the KP3, the relevant patches are
called SMP or LP.