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Michael Hayes 14 years ago
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69
extra/mmelody.c
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@ -7,75 +7,6 @@
#include "mmelody.h"
/* By default notes are in the scale C4 -> C5.
Note the first 12 frets on a six string guitar covers 3 octaves
from the pitch E2 (82.41 Hz) to the pitch E5 (659.26 Hz).
Tunes are specified using the notation C4C5F4G4C4 but for brevity
this can be simplified to C4C5F4GC where the previously specified
octave number persists. A problem with this notation is the
verbosity when we have something like B2C3B2C3. Most melodies will
only require 2 and 3 at the most octaves. The ABC music notation
uses CDEFGABcdefgabc'd'e'f'g'a'b'c' to denote 3 octaves from C2 to
C5? This uses numbers to indicate note duration, for example, C2
denotes a C of twice the standard duration.
By default notes are crotchets (quarter notes) and tempos are
defined in beats per minute. If we assume 4/4 time, then each beat
has a quarter-note duration.
The note duration can be halved with a comma suffix, e.g., A,
The note duration can be extended by a half with a dot suffix, e.g., A.
The note duration can be doubled with a slash suffix, e.g., A/
The note duration can be trebled with two slash suffixes, e.g., A//
(this can be continued to lengthen the note).
If there are lots of quavers (eighth notes), then the default note
duration can be switched using *8. *4 returns to quarter note timing.
Rests are specified with a space character. The timing modifiers ,
. and / can be used.
<ABC> is equivalent to ABCABC
<ABC>3 is equivalent to ABCABCABC
ABC: performs an infinite repeat of ABC
<ABC]1DE]2FG> represents ABCDEABCFG where ]n denotes alternate
endings.
A+ sounds an octave higher
A- sounds an octave lower
@120 sets the tempo to 120 beats per minute
This could be made a lot more flexible but the orginal
implementation had a tight memory constraint. Possible extensions:
* For emphasis perhaps use ^ to indicate louder, for example, C^.
Similarly, to make a note quieter it could have a v suffix.
* Use | for bar markers; these can be ignored.
* Time signatures.
* Nested loops, e.g., <AB<ABC>>
* sixteenth notes? Perhaps A,,
* Perhaps lower case for eighth notes?
* Triplets and other irrational tuplets? A triplet quarter note
has 2 / 3 the duration of a quarter note while a triplet eighth note
has 2 / 3 the duration of of an eighth note. This can be achieved
using *6 or *12.
*/
enum {MMELODY_SCALE_SIZE = 12};
/* Assume each beat is a quarter note. */

78
extra/mmelody.h
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@ -3,6 +3,84 @@
@date 20 April 2007
@brief Play simple melodies.
*/
/* By default notes are in the scale C4 -> C5.
Note the first 12 frets on a six string guitar covers 3 octaves
from the pitch E2 (82.41 Hz) to the pitch E5 (659.26 Hz).
Tunes are specified using a sequence of characters representing
notes, periods, and control operations.
A note consists of the note name, followed by the octave number.
For example, middle C is C4.
A simple melody could be represented by C4C5F4G4C4 but for brevity
this can be simplified to C4C5F4GC where the previously specified
octave number persists.
A problem with this notation is the verbosity when we have
something like B2C3B2C3. Most melodies will only require 2 and 3
at the most octaves. In contrast, the ABC music notation uses
CDEFGABcdefgabc'd'e'f'g'a'b'c' to denote 3 octaves from C2 to C5.
This uses numbers to indicate note duration, for example, C2
denotes a C of twice the standard duration.
By default notes are crotchets (quarter notes) and tempos are
defined in beats per minute. If we assume 4/4 time, then each beat
has a quarter-note duration.
The note duration can be halved with a comma suffix, e.g., A,
The note duration can be extended by a half with a dot suffix, e.g., A.
The note duration can be doubled with a slash suffix, e.g., A/
The note duration can be trebled with two slash suffixes, e.g., A//
(this can be continued to lengthen the note).
If there are lots of quavers (eighth notes), then the default note
duration can be switched using *8. *4 returns to quarter note timing.
Rests are specified with a space character. The timing modifiers ,
. and / can be used.
<ABC> is equivalent to ABCABC
<ABC>3 is equivalent to ABCABCABC
ABC: performs an infinite repeat of ABC
<ABC]1DE]2FG> represents ABCDEABCFG where ]n denotes alternate
endings.
A+ sounds an octave higher
A- sounds an octave lower
@120 sets the tempo to 120 beats per minute
This could be made a lot more flexible but the orginal
implementation had a tight memory constraint. Possible extensions:
* For emphasis perhaps use ^ to indicate louder, for example, C^.
Similarly, to make a note quieter it could have a v suffix.
* Use | for bar markers; these can be ignored.
* Time signatures.
* Nested loops, e.g., <AB<ABC>>
* Sixteenth notes? Perhaps A,,
* Perhaps lower case for eighth notes?
* Triplets and other irrational tuplets? A triplet quarter note
has 2 / 3 the duration of a quarter note while a triplet eighth note
has 2 / 3 the duration of of an eighth note. This can be achieved
using *6 or *12.
*/
#ifndef MMELODY_H
#define MMELODY_H

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