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BoxyLady user manual

This section describes functions used within notes mode that can alter the tuning system, or even the entire notation system. They are sufficiently complicated as to be worthy of their own sub-page.

tuning(TYPE)
tuning(type=TYPE key=NOTE): TYPE can be one of several different modes. The note A is selected as that which is kept constant under different tunings. In the second syntax, NOTE represents the central note of the tuning system, used for unequal temperaments (defaults to c in the first syntax). For music in C major, a value of c, g, or d is probably most appropriate.

12tet
The default, 12-tone equal temperament. Note finer accidentals than the semitone are available, and so this tuning is effectively 48-tone.
19tet
19-tone equal temperament. Notes enharmonically equivalent under 12tet are not under 19tet. A chromatic scale is as follows: c cis des d dis ees e eis f fis ges g gis aes a ais bes b bis c.
31tet
31-tone equal temperament. Similar to the above.
10tet
10-tone equal temperament. Only 5 named notes at each octave, c d e/f (tuned alike) g & a/b (tuned alike), are available, with accidentals available as normal. Potentially suitable for gamelan.
14tet
14-tone equal temperament. All 7 named notes are equally spaced through the octave.
15tet
15-tone equal temperament, which is not a meantone temperament. CD, FG and GA (major tone) are wider intervals than DE and AB (minor tone). Changing key requires either complex use of accidentals, or use of the notes() function.
22tet
22-tone equal temperament. Similar concerns to the above.
pelog
Pelog scale based on 9-tone equal temperament. Note names are "ji","ro","lu","pat","ma","nem", and "pi".
slendro
Slendro scale based on 5-tone equal temperament. Note names are "ji","ro","lu","ma",and "nem".
Pythagorean
Meantone based on the perfect fifth. Twelve tone only.
Ptolemy
Ptolemy's just scale, with accidentals added.
harmonic
Based on natural overtones of the fundamental key.
Harrison
An original idea by John Harrison, tunings based on π are also known as Lucy tuning. This tuning is based on circles of fifths which are slightly smaller than that of equal temperament.
4cmt
Quarter-comma mean-tone.
BPLambda
A non-octave scale, this is the lambda mode of the Bohlen-Pierce scale. It uses extra note names: h and j, which are beyond g, and notes repeat at the interval of a tritave (12th) not octave (8th).
WCAlpha
Wendy Carlos's Alpha scale (non octave). It is equal tempered, with 9 pitches per perfect fifth. Thus, there are no true octaves and <c c'> represents a stretched octave. Standard note names are used.
WCBeta
Wendy Carlos's Beta scale. As above, but 11 pitches per perfect fifth.
WCGamma
Wendy Carlos's Gamma scale. As above, but 20 pitches per perfect fifth.
With quarter-tones and third-tones also available, the above selection of equal temperaments means the octave can be successfully divided into the following numbers of equal pitch classes, amongst others.
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 18, 19, 20, 21, 24, 28, 30, 31, and 38.

tuning() only offers a subset of the flexibility offered by gamut(...) which allows complete reconstruction of the notation and tuning system!

The gamut function is modal, in that the instructions within it are specialised and executed in order as follows...

new(): resets the gamut and starts again from scratch, otherwise settings from the current gamut (as either edited or created by tuning()) are preserved.

tuning(...): can also be used within gamut().

pitch_classes=N: sets the number of pitch classes per octave (or pseudo-octave) to N. This clears the "pitches", "note_names", "notes", and "accidentals" tables.

note_names(c d e f ... LIST OF NOTES): sets the list of allowable note names to be used in notes mode (not including accidentals or articulation). These can be multi-character. They are case sensitive, and can also contain numbers and other legal characters, except ' - ,. Even r is allowed. Certain note names (such as r or numbers) already have music functions, however any note name can be prefixed when used by ' to avoid conflicts. (Any bare token encountered in notes mode is assumed to be a note name if prefixed so.) Setting note_names clears the "notes" and "accidentals" tables.

notes(0 2 4 5 7 ... LIST OF INDICES): maps note names to an index within the set of pitch classes, starting from zero. This must be the same length as note_names(). Fractional indices are allowed, but indices must be within the range 0 to pitch_classes. Fractional note values are interpolated between the nearest two pitches, linearly on pitch scale.

accidentals(ACC1(OFFSET) ACC2(LIST OF OFFSETS) ...): creates a rule for accidentals.

ACC1 ACC2 etc. must be unique and not cause confusion with note names as they are directly opposed. No accidentals are created by default.

If a single offset is ascribed to an accidental (positive or negative) than this acts as an offset to the index into the pitch class table for all notes. In 12-tone equal temperament, a typical basic requirement is to set sharps to +1 and flats to -1. E.g. accidentals(es(-1) is(1)).

If a list of offsets is given, this must be one per note name. Offsets may be fractional, e.g. for half-sharps. Any legal character can be used in accidental names except ' - ,.

standard_accidentals(A): creates the "standard set" of accidentals, where A is the number of pitch classes corresponding to a full sharp of flat (which does not have to be an integer). A is often equal to 1.

notes_meantone(tone=M half=H): assigns offsets and number of pitch classes automatically assuming M and H represent the number of steps in tones and half-tones, and an octave is made up only of these intervals. Also, assigns the standard set of accidentals, assuming a sharp or flat is equivalent to the difference in size of M and T. For standard tuning as on a piano, M=2 and H=1.

notes_twotone(major=M minor=Q half=H): is similar, but allows for the exotic effect of major and minor tones to have different numbers of steps. Harmony becomes very complicated under these circumstances!

repeat_ratio=F: sets the size of the octave or pseudo-octave to a value F (of type FREQ_RATIO). F=2 is typical.

equal_tempered(): requests BoxyLady calculate pitch classes automatically as even-tempered. repeat_ratio must be set first.

generator(note(NOTE) r=R g=G n=N step=S): requests BoxyLady calculate pitch classes automatically using a generator. Multiple calls to generator() are possible. Starting with a pitch ratio of R at note NOTE (not centered upon note NOTE; rounded down in case of fractions), BoxyLady makes N steps through the pitch classes of size S (positive or negative), at each step multiplying R by G and inserting this new ratio into the pitch classes table. Wrapping is done automatically when steps go out of bounds, thus repeat_ratio must be set prior to generator(). R and G have FREQ_RATIO format. If pitch_classes and S are coprime, one call to generator of size pitch_classes will fill the whole table. The starting value of R can be arbitrarily set to 1 unless multiple generators at different start notes are needed.

pitches(LIST OF FREQ_RATIO): manually sets the pitch table. The number of parameters must equal pitch_classes. Typically, the first entry is set to 1, although all that matters is that the pitch ratios are relatively correct.

pitch(note(NOTE) r(FREQ_RATIO)): sets a single pitch in the pitch table, identified by note name.

move_pitch(note(NOTE) r(FREQ_RATIO)): as above, but moves relative to previous value.

rotate_pitches(note(NOTE)): rotates the set of pitches such that the current first pitch class is now assigned to NOTE. This can be used to change the home key for regular temperaments.

standard(note(NOTE) r=R): sets the base pitch to which all others are related. For those tuning systems generated automatically, e.g. at program start-up, this defaults to the note a'''' corresponding to a frequency ratio of R=1. However, not all tuning systems generated by the user need have an "a" at all! Whichever note is set will correspond to a sound sample played at its natural sample rate, assuming no transposition is imposed.

list(type=T tol=TOL limit=LIMIT): shows the pitch table. T can be "diatonic", "chromatic", "auto", or omitted which will display either the standard notes C-B, all 12-tone pitches, the current list of note names without accidentals, or all pitch classes. LIMIT if specified as an integer sets the limit assumed for tuning to identify fractional formats of pitch ratios, e.g. 5-limit. TOL is the tolerance, in cents, for identifying fractional formats of pitch ratios, if specified.

The following is a simple example to generate 12-tone equal temperament (which is built in anyway in fact).

gamut(
	new()
	pitch_classes=12
	note_names(c d e f g a b)
	notes(0 2 4 5 7 9 11)
	standard_accidentals(1)
	repeat_ratio=2
	equal_tempered()
	standard(note(a'''') r=1)
)
/pre>

A simpler example still might only change the repeat ratio once 12-tet is already set up (as at program start-up).

gamut(
	repeat_ratio=2.05
	equal_tempered()
	standard(note=a'''' r=1)
)

There are a lot of potential uses for gamut().

  • Defining custom note names such as "ding", "ut", or "h".
  • Other European note naming systems, such as German.
  • Custom accidentals such as "#" as a name, or odd intervals.
  • Non-octave repeating scales.
  • Custom tuning systems or microtonal scales.
  • World music: Non-Western or non-standard notation systems that do not use the a, b, c notation.

intonal(rel=REL tuning(...) gamut(...))
This function implements intonalism. Either tuning(...) or gamut(...) can be used to specify the tuning system as defined above. If REL is specified, then transposition is carried out such that this note has an equal value in both the old and the new tuning system. If it is omitted, then the previous note is kept equivalent instead.