Adventures with the Pete Walton microtonal plug-in

I posted the following to the Sibelius website. I thought that maybe
somebody using Sibelius might be interested in it:

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Adventures with the Pete Walton Sibelius microtonal plug-in

I wanted to make a short post concerning my recent activities with
Pete Walton's excellent microtonal plug-in for Sibelius.

If you recall, Pete has created a plug-in that will automatically
adjust pitch-bends for a microtonal temperament which is user-
specified.

Basically one specifies, in the plug-in, the cents deviations from a
given set of Sibelius accidentals. Let's take an example: Cbb,
C3/4flat, Cb, C1/4flat, C, C1/4sharp, C#, C3/4sharp, Cx.

So, at maximum, using NON-equivalence of enharmonics, it's
possible to use these 9 native Sibelius symbols times the 7 "white
note" names for a total of 63 pitches. Indeed, Pete has created
a 63-tET temperament to test the upper extreme of this system.

Since the upper limit is 63, it's not possible to make a
temperament of the full 72-tET temperament, an extremely versatile
system, since our "regular" 12-equal is imbedded in it. (In
fact it consists of 6 different 12-equal scales transposed against
each other by simple just intonation ratios!!)

However, I was able to create a 21-note subset of 72-tET, which has
been called the "Blackjack" scale on the Internet Tuning
List, after the 21 pitches.

It's pretty easy to alter Pete's plug-in to adapt it to any
given temperament, simply by entering in the alterations in cents
values for each Sibelius accidental from the pitch Sibelius would
normally play.

There are a couple of things one must be careful about. One, which
initially confused me quite a bit when working with this, was the
fact that when using the Sibelius quarter-tone FLAT accidental,
Sibelius is altering the pitch a semi-tone below the given note. For
example, "E-quartertone flat" is actually Eb raised by a
quartertone. This solves the mysterious situation, probably noticed
by anyone who has run the Sibelius quartertone plug in, that both
quartertone FLATS and quartertone SHARPS have the same pitch bend:
~B0,80 !! (One would think a quartertone flat should be ~B0,48. So
if anybody is encountering strange goings on when trying to alter
quartertone playback by pitch bends, this is what is causing it. (It
stumped me for some time…)

Pete's terrific plug-in creates the pitch bends for us, so we get
appropriate pitch bends for our temperaments. In the case of 72-tET
we get the following numbers, in case anybody is interested in
manually entering in this wonderful, practical and versatile
temperament. (Anybody think I like this temperament?? :))

A "convention" has been established on the Internet Tuning
List to use the following ascii accidentals which emulate the Sims
written ones:

^ = twelfth-tone high (an arrow)
v = twelfth-tone low

> = sixth-tone high
< = sixth –tone low

] = quarter-tone high
[ = quarter-tone low

Using the Pete Walton plug-in, we find the following values for these
accidentals. This is using the "refined" scale for pitch
bend. I was never quite sure how this operated until Pete explained
it to me: basically the "coarse" number is the number
furthest to
the RIGHT. The "fine" number runs from 1-128 and is the first
number, or the number to the left.

So we can go from ~B0,64 to ~B128,64 and then from ~B0,65 to ~B128,65
and so forth. ~B0,64 is actually the "regular" or natural
note, and it's possible to bend a whole step down from this pitch
and a whole step up from this pitch. That means ~B0,128 is a whole
step up, ~B0,96 is a semitone bend up, ~B0,64 is "normal,"
~B0,32 is a semitone down and ~B0,0 is a whole tone down. Since there
are a total of 16384 bend units (128 x 128) in the two whole note
span (400 cents), the resolution of the pitch bends is: 400/16384
= .0244 cents. Not bad.

It's hardly "rocket science" to realize that a
quartertone is a bend
of 16 up or ~B0, 80, and a quartertone bend down: ~B0,48. As I
mention above, however, there is the anomaly that, in the use of the
quartertone FLAT, Sibelius starts on the semitone BELOW and bends
up. This results, as mentioned, in both the quartertone up and
quartertone down having the same pitch bend, ~B0,80. Try the simple
quartertone playback plug-in which comes with every copy of Sibelius
and you'll see what I mean, if you don't know that already.

Simple arithmetic will give us the correct coarse pitch bends for the
12-th tones up and down and 6th tones up and down of the Sims 72-tET
system, but the correct numbers of both coarse and fine as realized
by the Pete Walton plug-in are as follows:

^ = twelfth-tone high (an arrow) ~B56,69
v = twelfth-tone low ~B72,58

> = sixth-tone high ~B71,74
< = sixth –tone low ~B57,53

] = quarter-tone high ~B0,80
[ = quarter-tone low ~B0,48 [or ~B0,80 with the quartertone flat as
mentioned]

Now if one is to actually use the Sims-Maneri, symbols, one needs to
use the Postscript font created by New York cellist Ted Mook for this
purpose. Mook plays many just intonation pieces in 72-tET, including
Harry Partch. Some people find that heretical, but it does come very
close to just intonation and in a practical manner.

https://www.mindeartheart.org/micro.html

Given the fact that each pitch of a scale such as "Blackjack"
which uses many of the Sims accidentals has a special accidental on
just about every note of the scale except two, one has to decide if
the Pete Walton plug-in facilitates that particular scale as opposed
to manually entering in the pitch bends according to the bend numbers
given above. Since it's so very easy to copy Technique text in
Sibelius from one note to the next, and since the 72-tET system uses
a very few symbols, it's extremely easy to "alt-click"and
just copy the bends to the notes.

So, possibly that kind of scale, which uses so many symbols, could be
just as easily done manually. There is also the situation that the
quartertones provided by Sibelius are not the ones used by Sims! He
has his own, that look a little like square-root signs. Personally I
find the Tartini ones that Sibelius uses more elegant, but it is a
fact that many performers who are working in 72-tET now (and indeed
there are several now, one trombonist, in fact, is still coming over
this night for a rehearsal!) are very much used to the Sims symbols,
and would prefer that they be used.

This means that the quartertone symbols generated by Sibelius
actually have to be REMOVED after the plug-in is run, since there is
no way to HIDE accidentals without hiding the given NOTE in
Sibelius. (That could be very convenient, and actually would have
been quite useful for a gentleman who posted recently on notating
scores where accidentals only apply to the notes they immediately
precede, very common in contemporary music, of course.)

One has to figure out the pitch bend numbers for this based upon the
fact that the Sibelius quartertones are REMOVED after the
temperaments plug-in is run! That really isn't very difficult,
but it did present a puzzling quandary for a while.

The Pete Walton plug-in works even better for temperaments such as 19-
tET, which use just our "regular" accidentals, but without
enharmonic equivalence. There are no "extra" symbols to
import in
that case. One could just select all the notes on one staff of the
score, run the plug-in and voila!

Of course, our standard 12-equal pitches do not work in 19-tET, which
is one of the terrific advantages of 72 over practically every other
system.

I really wish that somebody would have explained this all to me in
the way that I am explaining this all to me, so I hope some of it has
been useful! :)

To get the plug-in, please contact Pete Walton at:

pete@pswalton.freeserve.co.uk

Pete was extremely patient in explaining all of this, and will help
anybody interested in using his plug in or in "plugging in"
one's own temperament into the plug-in, as I did.

Joseph Pehrson