CP/M/CPM_CDROM.iso/simtel/sigm/vols000/vol056/optns.doc

Text File | 1984-04-29 | 15.5 KB | 546 lines

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V. OPTION LINE DESCRIPTION

Option lines are used in Musicraft to support musical functions
not handled by song lines. These functions are:

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{i:-8
1.
Call a chorus
{i:-8
2.
Label a song line
{i:-8
3.
Mark a measure
{i:-8
4.
Set or change the number
of intervals per octave
{i:-8
5.
Mark the end of a repeat
{i:-8
6.
Set or change the tempo
{i:-8
7.
Set or change the waveforms
{i:-8
8.
End a chorus

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Two musical functions use more than one option line,
specifically, the chorus function and the repeat function.
These two functions are discussed first and then each option
line is discussed in detail.


V.A. Chorus Function

A chorus (also called a refrain) is a segment of music which
must be performed several times in the course of a song.
Having to input the chorus each time would become tedious.
You can save yourself the work by entering the chorus once
and using the C_option, L_option and X_option lines to create
the effect.

A chorus must be indicated to Musicraft by placing an
L_option line in front of the chorus and an X_option line
at the end of the chorus (each of these option lines will
be discussed further below) as in the following example:

{l:Song part:
{m:2
{l:(song body segment 1)
{l:*C ABCXYZ
{l:(song body segment 2)
{l:*C ABCXYZ
{l:(song body segment 3)
{l:*X

{i:-8
Chorus part:
{l:*L ABCXYZ
{l:(chorus segment)
{l:*X

{m:1
{l:The effect of this structure will be the following:

{m:2
{i:-8
1.
Song body segment 1 is performed.
{i:-8
2.
Chorus segment is performed.
{i:-8
3.
Song body segment 2 is performed.
{i:-8
4.
Chorus segment is performed.
{i:-8
5.
Song body segment 3 is performed.
{i:-8
6.
The song ends.

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You cause the chorus to be performed at a point in the
song by placing the C_option line into the song at that
point. PLAY will, in effect, insert the entire chorus
into the song at that point and perform it before moving
on to the next song line after the C_option line.

The chorus must be placed at the end of the song. You can
have as many choruses as you like (up to 128) but
you must place them at the end of the song. (If you are
familiar with computer programs then you probably recognize
the similarity between the chorus and the subroutine.)

It is possible for a chorus call to appear in any segment
of a song. This includes placing a chorus call within a
chorus.  What if a chorus calls another chorus?  A chorus
may call another
chorus which can, in turn, call another chorus, and so on
for a "depth" of 16 choruses. But there is one
rule you must ABSOLUTELY follow: don't permit a chorus to
call itself, or to call another which, in turn, calls the first.
This situation will result in what computer programmers
sometimes call an "unbounded recursion". In other words,
it will
not stop until PLAY calls a halt to the introversion by
canceling the song when the "eight_deep" rule is violated.
But you can use the "nested call" capability for some
very powerful structural developments if it doesn't
confuse you.

Incidentally, the chorus function is useful for song segments
which must be repeated but which have different endings after
each repetition. A possible structure might be the following.

{m:2
{l:*C X1234
{l:(ending of first repetition)
{l:*C X1234
{l:(ending of second repetition)
{l:(rest of song)
{l:*X

{l:*L X1234
{l:(body of repeated section not including endings)
{l:*X

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V.B. Repeat Function

A song segment can be performed up to 256 times using the
L_option and R_option lines. The song segment to be repeated
must be indicated to Musicraft by placing an L_option
line in front of the segment, and placing an R_option
line at the end of the segment. Repeated segments may
occur at any time in a song and can occur in choruses.

The normal form of a repeated segment is

{m:2
{l:*L XYXYXY
{l:(song segment 1)
{l:*R XYXYXY   01
{l:(song segment 2)

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In this instance, song segment 1 will be performed two
times (once without the repeat and once for the repeat.)
Song segment 2 will be performed following the completion
of the repeat.

Repeated song segments can be part of other repeated song
segments and this condition is called a "nested repeat".
Should you wish to repeat a song segment more than the
256 times permitted with one repeat option line,
follow it with a second repeat option line. This extends
the number of possible repeats to 256 times 256, or 65,536
times.

An example of a nested repeat might appear as follows.

{m:2
{l:*L PIPES
{l:(song segment 1)
{l:*L SATYR
{l:(song segment 2)
{l:*R SATYR   01
{l:(song segment 3)
{l:*R PIPES   01
{l:(song segment 4)

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Here, the following events will occur.

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{i:-8
1.
Song segment 1 is performed once.
{i:-8
2.
Song segment 2 is performed once.
{i:-8
3.
Song segment 2 is repeated once.
{i:-8
4.
Song segment 3 is performed once.
{i:-8
5.
1, 2, 3, and 4 are repeated once.
{i:-8
6.
Song segment 4 is performed once.

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There is a situation that must be avoided in the use of
more than one repeated song segment. When the last part
of one repeated song segment overlaps with the first
part of a second repeated song segment, the combination
will never terminate. This situation also has a name
among programmers (these things happen to them but
shouldn't) and it causes an "infinite loop". If you
want to hear the rest of your song, avoid this situation.

{m:2
{l:*L 123.5
{l:(song segment 1)
{l:*L INFINITY
{l:(song segment 2)
{l:*R 123.5    01
{l:*R INFINITY 01

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Incidentally, when the repeated segment is completed, the
R_option line is reset so that the next time the repeat
is invoked by your song, the proper number of repeats will
again take place.

The R_option can be used to bypass a segment of music when
you want to skip a segment the first time but intend to
play it later as in the following example.

{m:2
{l:(song segment 1)
{l:*R JSBACH   01
{l:*L VIVALDI
{l:(song segment 2)
{l:*L JSBACH
{l:(song segment 3)
{l:*R VIVALDI  01
{l:(rest of song)

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In this example, song segment 2 will not be played until
after the first playing of song segment 3. Note that, if
you use a repeat to bypass a segment of music and that
repeat is "nested" within a true repeat, you should
indicate a large repeat count for the bypass repeat. This
is necessary because PLAY will decrement the repetition
counter each time the repeat is encountered and when it
reaches zero the repeat will be ignored.


V.C. Chorus Call Option Line

The C_option line is used to cause a chorus segment to be
performed in place of the C_option itself. The C_option
line is compiled by COMP and passed as part of the song
to PLAY.

A song may have as many C_option lines as are desired up to
the limit of your computer to hold song/option lines in memory.

The C_option has one part following the "C" identifying
the option. This is the name of an L_option line marking
the beginning of a chorus. The name must match some label.
Otherwise, COMP will report an error and not complete the
compilation of your song.

Examples:

{m:2
{l:*C CHORUS1
{l:*C REFRAIN
{l:*C 5
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V.D. Label Option Line

The L_option line is used to mark the beginning of a song
segment. It is compiled by COMP and use to resolve label
references made by R_option and C_option lines, and it
is passed as part of the song to PLAY. You might use the
L_option line for several reasons:

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{i:-8
1.
to indicate the beginning of a chorus segment;
{i:-8
2.
to indicate the beginning of a repeat segment;
{i:-8
3.
to indicate the beginning of a randomly selectable
song segment in the modified performance mode;
{i:-8
4.
to mark a convenient point in the song for use
in the FIND function of EDIT. (You can read
about this function in the EDIT section below.)

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A song may contain up to 128 labels. Any more than this and
COMP will declare an error in your song.

The L_option line has the following two parts beyond the
L_option
indicator. You provide these when you place the L_option
line in the song.

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{i:-8
1.
A name which uniquely identifies the segment;
{i:-8
2.
The segment select key for PLAY.

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The label name is used by the C_option line and the R_option
line to make reference to the L_option line. It may be
any sequence of from one to 8 characters in
length. The label name does not have any meaning in itself,
incidentally, only in its reference by other option lines.
Examples are

{m:2
{l:PART_A
{l:REPRISE
{l:DEVELOP
{l:CODA
{l:REPEAT
{l:RPM.78
{l:etc...

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The select key (also referred to as the label key) is used by PLAY
to permit modification of
the normal performance process into any sequence you might
desire.  This feature is discussed at length in the PLAY
section of the manual. Any key on your keyboard (excluding
control keys) may be
assigned to the label. If you wish to use the feature,
it is your responsibility to insure
that the keys assigned
to the different L_option lines are unique.

For additional information, see the discussion about the Modified
Performance Mode in paragraph IV.E.6.b. above.
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V.E. Measure Option Line

The M_option line is used to mark measures within a song.
It is passed as part of the song to PLAY for use in the
rehearsal mode of PLAY. The M_option line is the only option
which can be generated without the use of the
OPTION menu of the EDIT program. You can insert an M_option
line at any time when you are in the Edit and Insert modes
of EDIT.

A song may have as many M_option lines as are desired up to
the limit of your computer to hold song/option lines in memory.

The M_option line has one part following the "M" identifier.
A four-digit measure number is placed into the M_option line
by EDIT. This number is in order of use and is not necessarily
in order from beginning to end of the song. When you strike the
"M" key, the number is incremented and then used. Should
you place a measure into a song at some point, then back up
and place another M_option line before the first, the numbers
will be backwards.

Example:

{m:2
{l:*M 0001
{l:(measure segment 1)
{l:*M 0002
{l:(measure segment 2)
{l:*M 0003
{l:(measure segment 3)
{l:...etc.

{m:1
EDIT renumbers all M_option lines when it saves the
song on floppy disk.


V.F. Microtone Option Line

The #_option line is used to set or change the number of intervals
within an octave. It is used by COMP in compiling song lines which
use the microtone notation and is not passed as part of the song to
PLAY.

The song may have as many #_option lines as desired up to the limit
of your computer to hold song/option lines in memory.

The #_option has one part following the "#" identifying the option.
You must enter a number between 1 and 99 which specifies the number
of intervals per octave that is to apply to note information which
follows the #_option line.

If you do not use #_option line anywhere within the body of a song,
COMP will declare microtonal information as errors.
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V.G. Repeat Option Line

The R_option line is used to mark the end of a repeated song
segment. It is compiled by COMP and passed as part of the
song to PLAY to control performance.

A song may have as many R_option lines as desired up to the
limit of your computer to hold song/option lines in memory.

The R_option has two parts following the "R" identifying
the option.

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{i:-8
1.
The segment name in the beginning L_option line.
{i:-8
2.
The number of repetitions of the segment.

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The name must match some label preceding the R_option line;
otherwise, COMP will report an error and not complete the
compilation of your song.


V.H. Tempo Option Line

The T_option line is used to set or change the tempo of
the music which follows the point at which the option is
used. It is used by COMP in the computation of duration
and pitch information to be passed to PLAY. The T_option
line is not passed to PLAY.

A song may have as many T_option lines as desired up to the
limit of your computer to hold song/option lines in memory.

The T_option has one part following the "T" identifying
the option. You must enter a number between 1 and 999 which
specifies the number of quarter notes to be played per
minute. This notation is like the standard Maetzel notation
used in most published music today.

If you do not use a T_option line anywhere within the body
of a song, Musicraft will play about 80 quarter notes per
minute.

Example:

We would like to play a song at 120 quarter notes per minute
for the first 20 measures, but, beginning at measure 21,
we would like to change the speed to 144. The following
example shows this.

{m:2
{l:*T 120
{l:(song segment 1)
{l:*T 144
{l:*M 0021
{l:(song segment 2)


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V.I. Waveform Option Line

The W_option line is used to permit the setting or changing
of the sound color of the music which follows the point at
which the W_option line is placed in the song. The W_option
line is compiled and passed as part of the song to PLAY.

PLAY permits
up to 14 different waveform tables to be available for use
in performance of a song. These tables are numbered from 1
to 14. You relate these tables to the voices of your song
by using the W_option line. By placing a waveform into a table
referenced by a W_option line, you will have caused PLAY to
use that particular sound color in the performance of a voice.

If you do not use a W_option line anywhere within the body of
a song, PLAY will use table 1 for all voices in the song.

A song may have as many W_option lines as desired up to the
limit of your computer to hold song/option lines in memory.

A W_option line has as many parts following the "W" identifier
as the number of voices you have declared for the song. If
you declare three (3) voices, the W_option line has three
(3) additional parts. Each part corresponds to a voice. The
first part corresponds to the first voice, the second part
to the second voice, and so forth. You may
place any number from 1 to 14 in each part and thereby
associate that numbered waveform table in PLAY with the voice
corresponding to that part of the W_option line. This
association will hold from that point until the occurrence
of another W_option line.

Example:

In a 3_voice song, we would like to use table 3 with voice
1, table 10 with voice 2, and table 2 with voice 3. The
following W_option line will produce these results:

{m:2
{l:(song segment 1)
{l:*W 03 10 02
{l:(song segment 2)

{m:1
Song segment 1 will be performed by PLAY using table 1 for
all three voices while song segment 2 will be performed
in the manner described above.


V.J. Chorus Exit Option Line

The X_option line is used to mark the end of a chorus or the
end of a song when a chorus is used. It is compiled by COMP
and passed as part of the song to PLAY.

If the X_option line is preceded by
a corresponding L_option line, then it causes PLAY to return
to the main body of the song following the C_option line
which caused the chorus to be performed. If it is not preceded
by a corresponding L_option line, then the song is terminated.
You should use this feature to end songs which have choruses.
If you omit the use of the X_option line in a song which has
a chorus, then the chorus will be played one last time and the
song will then terminate. See the discussion about the Chorus
Feature above for more information.
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