JACKY LIGON'S EXPERIMENT READY

Jacky Ligon's new experiment... an "All Prime Scale" constructed of
interval ratios involving only prime numbers is now ready in the
Tuning Lab!

http://artists.mp3s.com/artists/140/tuning_lab.html

Scale ratios: 1/1, 19/17, 13/11, 29/23, 7/5, 3/2, 11/7, 5/3, 23/13,
13/7, 2/1.

In Jacky's own words:

A long time fascination with prime numbers and their
relationship to tuning theory has led me to explore
scales in which both the numerator and denominator
are prime numbers. Below are the values for a first
order "All Prime Scale" from my Just Intonation
spreadsheet.

Ratio
Cents Value
12TET
Cents Adjust
Consecutive

1/1
0
0.00

31/29
115.4583783
100
15.46
115.4583783

19/17
192.5576066
200
-7.44
77.09922832

13/11
289.2097194
300
-10.79
96.65211277

29/23
401.3028469
400
1.30
112.0931275

17/13
464.4277477
500
-35.57
63.12490085

7/5
582.5121926
600
-17.49
118.0844449

3/2
701.9550009
1.96
119.4428083

11/7
782.4920359
800
-17.51
80.53703503

5/3
884.358713
-15.64
101.8666771

23/13
987.7466855
1000
-12.25
103.3879725

13/7
1071.701755
1100
-28.30
83.9550698

2/1
1200
1200
0.00
128.2982447

I have created two simple examples of using this tuning
in a musical context, in which I improvise in Major and
Minor Diatonic modes in the key of C. The timbres
used are as follows:

A Harmonic Drone created using partials 1-16 (Various
Additive Techniques).

An emulation of Harry Partch's Cloud Chamber Bowls
(TX81Z).

An emulation of a Gamelan Orchestra Metallophone
instrument (TX81Z).

A Wood Flute (Sample).

Sometimes I find the "What if?" question to be the
driving motive that fuels many such exotic explorations.
One might expect the use of such high prime numbers
to produce a howling discordant effect, but I think that
this particular combination of timbres used in the
experiment lessened this perception, as well as the
familiar phenomenon of how our hearing tends to
perceptually "round downward" to more simple
integers. During my improvisational exploration of the
scale, I found that the 17/13 presented some very
interesting melodic possibilities, as the examples will
demonstrate.

Jacky Ligon

09/02/00