JI oscilloscope images

To: internet:tuning@onelist.com
Date: 03-06-99

I have an oscilloscope, nothing fancy, left over from when I dabbled in
digital circuit design, and I find it a terrific tool for demonstrating
the beauty of Just Intonation.

I put the scope in X-Y mode rather than sweep mode. This simply means
that it takes two inputs, one of which controls the horizontal position,
the other the vertical (in "normal" scope operation, the horizontal axis
is reserved for the sweep of time, and all inputs are expressed in the
vertical axis).

I run the output of my Korg M-1 synth to the scope: left channel to
horizontal and right channel to vertical (or the reverse; it doesn't
matter). Then I select a horn voice, using effects processor to
include unequal delay in L and R channels. Play chords (4:5:6 and
4:5:6:7 are solid starters) with and without JI tuning and voila!
Unbelievable, hypnotic results with JI; ugly chaotic mess with 12-tET.

I've had people tell me, when I previewed what they would see, that they
knew I was fibbing, then have watched their eyes bug out.

The best part is that newcomers are hearing chords that sound "wrong" to
their 12-tET-blasted ears, yet are seeing pictures that are clearly so
much more beautiful than those in ET. I think this might help them give
JI more hearings, before dismissing it as odd or uninteresting.

I have only one caution to others: be careful of your common ground. I
use a 10K resistor between the ground of the synth output and the ground
of the oscilloscope input, just in case the two of them want to fight
each other in any way (they probably won't, especially if they trace
back to the same wall outlet, a good practice!). The 10K is transparent
to the miniscule current needed to drive the scope input, but is enough
to limit the effects of any voltage disagreement between the two
instruments' grounds.

JdL

Those interested in JI oscilloscope images or laser images from vibrating
mirrors should check out:

Pellegrino, Ronald. _The Electronic Arts of Light and Sound_. New York: Van
Nostrand Reinhold, 1983.

He was doing such things as part of electronic music/light shows in the
70s. He now does video art and has a web site, which, last time I checked,
is at: http://www.microweb.com/ronpell/.

By the way, an excellent new site/foundation concerned with visual music
and abstract animation is at: http://www.iotacenter.org/. They have an
artists' links page that includes links to Pellegrino among many others.

Bill

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^ Bill Alves email: alves@hmc.edu ^
^ Harvey Mudd College URL: http://www2.hmc.edu/~alves/ ^
^ 301 E. Twelfth St. (909)607-4170 (office) ^
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