PERFORMANCE NOTES for DRIFT DHIKR INTERACTIVE by Dave Seidel (2005) - live
performance realizations by Art Hunkins.


Drift Dhikr Interactive is a live-performance rendition of Dave Seidel's
Drift Dhikr (Combination Study 2) for Csound.  The original scorefile, along
with recording and commentary, can be found at
http://www.mysterybear.net/article/12/drift-dhikr.  Study of these source
materials is highly recommended, as live performance of Drift Dhikr
Interactive is intended to model after the original work.

Drift Dhikr was composed in Csound, a software sound synthesis program; and
Drift Dhikr Interactive is performable in several current incarnations of
Csound4.  These versions, all free downloads, are: Maldonado's CsoundAV
(http: www.csounds.com/CsoundAV), Lazzarini's MyCsound4
(http://www.nuim.ie/academic/music/musictec/csound) and Ramsdell's
csoundgbs/flCsound
(http://sourceforge.net/project/showfiles.php?group_id=81968) - both console
and simple GUI (flCsound) mode.  All three Csounds are prebuilt for Windows
systems.

The new Csound-5beta (Windows - same URL as Ramsdell above, but part of
Gogins' CsoundVST package) is also capable of performing these realizations,
though only with ASIO soundcard drivers.  (Normally ASIO drivers are found
only with multi-channel soundcards; however, stereo cards can use the free,
handy ASIO4ALL driver 2.6 or later, located at http://www.asio4all.com.)

Various Csound binaries are also built for Linux and various Mac OS's; they
can be found at http://www.csounds.com (under Execs).  Some of these have
known issues with FLTK display and/or real-time audio and MIDI; but they may
well work with some or all versions of Drift Dhikr Interactive.

The performer must enable his/her chosen (Windows) Csound "variety" under
CsOptions in the selected performance (.csd) file (default is CsoundAV); any
other versions must be commented out by inserting a semicolon at the
beginning of their line.  CsOptions flags for Linux are similar to those for
MyCsound4 and csoundgbs/flcsound ("other Csound4's"), except that the audio
output device flag (-o) must be specified in a way unique to Linux.

The performance model - following the original Drift Dhikr - can be
described as follows: A sonority, comprised of combination and difference
tones related to two sine waves in a simple frequency ratio (originally
3/2), fades in.  This sonority soon begins to glide slowly and inexorably to
a final pitch ratio of 2/1 (with reference to the same base frequency).  The
sonority then fades out.

To this basic progression and framework, the interactive version adds two
*options*: 1) a delicate "harmonic glissando" effect which fades in prior to
the principal sonority, sustaining throughout and dissolving a) once the 2/1
pitch ratio is reached (and prior to its fade), b) together with the
principal sonority, or c) only after the principal sonority dissipates; 2)
one or two "stop points" along the glide, representing points of relative
consonance, where the glide pauses before continuing further in the same
direction (no "doubling back" allowed).  In addition to dwelling on these
"stop points," the performer may also prolong the areas of initial and final
pitch ratio.

All movement is evenly paced and gradual. Play time of the original Glide
Dhikr is 9 minutes, though longer lengths are highly desirable.  As a
result, 9 minutes should be regarded as an appropriate *minimum* length for
an interactive rendition.  (The principal challenge, particularly in the
MIDI versions, is to move the controls at a slow and steady rate without
jerking.  Longer-travel pots and sliders will facilitate this.)

There are twelve different versions of Glide Dhikr Interactive.  All are in
stereo.  Four basic versions use on-screen windows and mouse only, no MIDI
controllers.  The other eight require two to four (optionally five)
controllers; these bear the "m" suffix (e.g., dhikrm.csd).  The "+" suffix
indicates a *choice* of initial frequency ratios other than the basic 3/2,
while "3" in association with "m" allows pitch glide to be handled by up to
three controls instead of one.  (Besides giving longer potential travel to
the controls, these versions allow for one or two brief "stop points" to be
specified by the performer.)

The fact that MIDI versions of Drift Dhikr Interactive can be performed with
*only two controllers* - one an amplitude fader, the other a frequency
"glider" - presents interesting performance options: 1) Use of a basic MIDI
keyboard with only an overall (channel) volume controller (controller 7) and
modulation wheel (controller 1); 2) a Korg KAOSS Pad (X/Y MIDI controller);
or 3) any simple X/Y joystick (the simplest ones are best).

For this last option, and to convert joystick data to MIDI (which is
required), you need the handy, free MIDI Joystick v1.1 utility found at:
http://members.magnet.at/hubwin/midi.html (MDJSTK11.ZIP).  In addition, you
must install the (free) MIDIYoke MIDI "patch cable" driver found at
http://www.midiox.com.  (Note that for this application you do *not* need to
install MIDIOx.)  In MIDI Joystick, set the X and Y axes to Channel 1, the Y
axis Value to "reverse," and the controller numbers to whatever you intend
to choose on the .csd performance screen (controller 1 for X and 7 for Y
will match the defaults).  Select MIDI Yoke Junction 1 as "Out" and also as
MIDI Input port in your performance file.  (See the Addendum below for a
further performance option that permits control of the harmonic glissandi
with joystick buttons.  For a very basic, if awkward, press-and-hold
joystick Button A for harmonic glissandi in dhikrmh.csd and dhikrm+h.csd,
set MIDI Joystick Button A to Note, Channel 1, Value Down = 1 and Value Up =
0.)

All versions include an adjustable Base Frequency reference between 200 and
600Hz (default = 240Hz).

All versions also include an on-screen display of the *percentage* distance
travelled between the opening and closing frequency ratios.  This view is
particularly helpful in identifying and anticipating the relatively
consonant "stop points" along the way.  In the multiple frequency slider
versions ("3" suffix), these selected "stop points" may be preset as slider
endpoints (they too are expressed as a percentage).  Be sure that the second
"stop point" percentage is higher than the first, in order to continue with
the following control in the same direction.  Unused stop points are set to
100%.  It is probably best to divide the glide pitch range into fairly equal
percentages; otherwise, the control pot/slider rate of change may not be
consistent.

In the MIDI "h" versions (optional harmonic glissandi), you have the option
of assigning the harmonics a MIDI slider, or using the ALT(ernate) Start/
Stop Harmonics checkbox along with a preset (ALT) On/Off Time (necessarily
the same value for both On and Off).  The Off Time cannot be changed once
the sound has begun.

There are two additional methods for starting and stopping the harmonic
glissandi as well.  Instead of clicking the on-screen checkbox, one can
press any available MIDI button that can send a MIDI on and off message on
channel 1.  (This is the equivalent of holding down any key on a MIDI
keyboard - which, if desired, can also function as a Start/Stop Harmonics
control.)  This may be a more convenient way for the performer to control
the harmonics as there would then be no necessity actually to "perform" on
the *computer*.  Programmed buttons also permit the basic harmonic glissandi
versions to be performed on an X/Y joystick, in conjunction with MIDIYoke
(see above).

When multiple buttons are available, program one with the "Start" message,
another with "Stop."  Using a single button for "Start/Stop Fundamental"
(Note On/Off) will require holding the button down during much of the
performance, unless the button can be set to "toggle" between On and Off
(which is preferable).  The appropriate SysEx MIDI data string for Note On,
channel one is (in hex) "90 00 01"; for Note Off, "90 (or 80) 00 00".
(Buttons on the Peavey PC 1600[x] can be programmed with these MIDI
messages, for example.)  Otherwise, "NoteOn" event type can be selected,
along with any note name or number with a positive velocity value - channel
1.  (If required, "NoteOff" with same note name/number, or "NoteOn" with
same note name/number *and velocity equals zero* - also channel 1 -
terminates the event.  "Press/release" buttons do this automatically.)
Unfortunately, the limitations of MIDIYoke may require a single button to
be used with an *X/Y joystick* - held down for the duration of the
harmonics, as mentioned above.  (However, see the Addendum below.)

Non-MIDI "h" versions allow for independent selection of On and Off Times
for harmonics, and Off Time may be changed after the sound has started. 

In the MIDI versions, be sure to turn all pots/sliders to zero before
running the performance file.  (Otherwise tones may initialize as "on" -
which is not desirable.)  Zero position for a joystick is in the lower left
corner (see further below on joystick performance).

Specifics of the various versions follow.

DHIKR.CSD, DHIKR+.CSD, DHIKRH.CSD, DHIKR+H.CSD --

No MIDI controllers required; all performance is from an on-screen window
with mouse click (and/or CRSR movement).  Glide Time (approximately in
seconds) indicates any lag time from one *pitch* slider value to another
(variable during performance).  "+" versions give option of 11 initial
frequency ratios.  (These ratios represent semitones of Wendy Carlos'
"Super Just" just intonation scale; see
http://www.microtonal-synthesis.com/scale_carlos_super_just.html.)  "H"
versions add optional harmonic glissando effect.  Dhikr.csd most closely
parallels the original Glide Dhikr, using a 3/2 initial frequency ratio.

DHIKRM.CSD, DHIKRM+.CSD, DHIKRMH.CSD, DHIKRM+H.CSD --

Require two external MIDI controllers (pots or sliders).  Additional
controller for "h" suffix versions (on-screen control of harmonic glissandi
also an option - ALT Stop/Start, ALT On/Off Time).  Controller numbers are
specified on-screen.  (Make sure that all MIDI controllers transmit on
channel 1.)  Otherwise same as basic series above.

NOTE: All MIDI versions of Drift Dhikr Interactive provide for two
additional controller configurations that may be rarely encountered. 1) ALL
CONTROLLERS USE THE SAME CHANNEL, BUT NOT #1: Locate the line toward the
beginning of the performance file - "#define CHAN #1#", and change the
channel number to the one you need (from 2-16) with any text editor, such as
Notepad.  (This revision is active until you change it again.)  Note that
the "#" characters around the channel number must remain.

2) EACH CONTROL (of a hardware bank of 4-16) USES A UNIQUE CHANNEL, BUT WITH
(channel volume) CONTROLLER #7: For this situation, either the overall
Amplitude Controller # box (when applicable) or the Bank 1 1st Controller
box on the performance screen includes a special, coded controller number.
To enable this layout: For the Amp Controller #, select 128; for Bank 1 1st
Controller #, select -1. All controllers will now be on consecutive
channels, starting with the Banks, then the Amp Controller, and lastly any
other individual controllers.

DHIKRM3.CSD, DHIKRM+3.CSD, DHIKRM3H.CSD, DHIKRM+3H.CSD --

Require two to four external MIDI controllers (pots or sliders).  One to
three of these controllers cover (divide up) the frequency glide range.
Specify the *1st* Frequency Controller # of up to three contiguous glide
controllers you intend to use, on-screen.  "Stop points" select the
percentage of range covered by each pot/slider.  (Each successive slider
begins where the last ended.)  Additional controller optional for "h" suffix
versions (on-screen control of harmonic glissandi also possible).  Otherwise
same as previous MIDI series.


ADDENDUM: PERFORMING DHIKRMH.CSD AND DHIKRM+H.CSD WITH JOYSTICK CONTROLLERS

A special setup makes it possible to perform dhikrmh.csd and dhikrm+h.csd
with only an X/Y joystick - while turning the harmonic glissandi on and off
with the two joystick buttons.  This produces a full-featured performance
entirely using a simple joystick.  (The original, basic IBM style works best
- with spring action defeated.)  Here are the essential steps (these
instructions are an expansion of the joystick info above):

1) The MIDIYoke driver must be enabled for a minimum of two ports. (Do/check
this in Control Panel/Sounds and Multimedia/Devices/MIDI Devices and
Instruments/MIDI Yoke Junction/Properties/Settings).

2) In MIDI Joystick (Settings), set the X axis to Controller, Channel 1 and
Data to 7.  Set the Y axis to Controller, Channel 1 and Data to 1 (this will
match on-screen defaults). Also, set the Y axis Value to "Reverse."

3) In MIDI Joystick, set Button A to Note, Channel 1, Data to 0, Value Down
to 1 and Value Up to 2.  Set Button B to Note, Channel 1, Data to 0, Value
Down to 0 and Value Up to 0.  (Note: Do *not* set Button B Value Up to 2.)

4) In MIDI Joystick, select "Out" as MIDI Yoke Junction: 1.  Assuming your
2-axis, 2-button joystick is correctly installed under Control Panal/Gaming
Options, press "Start."  Moving the joystick, you should observe the MIDI
output of X and Y axes.

5) Install and run MIDIOx.  Under Options/Data Mapping, load the file called
dhikrmhJoy.oxm included in this distribution.  After making sure "Turn Map
On" is checked, click OK.

6) In MIDIOx, under Options/MIDI Devices, select MIDI Yoke Junction: 1 as
MIDI Input, and MIDI Yoke Junction: 2 as MIDI Output.

7) When running dhikrmh.csd or dhikrm+h.csd, select MIDI Yoke Junction: 2 as
MIDI In Device.

8) Finally, make sure your joystick is well calibrated (check this in
Control Panel/Gaming Options/Properties).  Observe in MIDI Joystick whether
both X and Y axes output values *all the way* from 0 to 127 (starting at 0
is important for the X axis, and both 0 and 127 values are crucial for Y).
Do not use any joystick to perform Dhikr that fails to meet these criteria.

9) In performance, the joystick starts in the lower left corner, moves to
the lower right, then all the way up, and lastly to the far left.  All
beginning and end points are extreme (0 and 127 MIDI values).  The joystick
should be moved to the lower left corner before the performance file is
opened.


Joystick button A should now turn on harmonic glissandi, and button B turn
them off.  The on-screen ALT On/Off Time continues to determine fade in and
out durations as discussed above.


Dave Seidel - dave at mysterybear dot com
  http://www.mysterybear.net/

Art Hunkins - abhunkin at uncg dot edu
  http://www31.brinkster.com/abhunkins

July/August 2005