Check whether a string is comprised exclusively of valid syntax for music strings. A music object can be built from such a string. It combines a noteworthy string and a note info string.
musical(x)
as_music(
notes,
info = NULL,
lyrics = NA,
key = "c",
time = "4/4",
tempo = "2 = 60",
accidentals = NULL,
format = NULL,
labels = NULL,
at = seq_along(labels)
)
is_music(x)
music_split(x)character or music, a string to be coerced or an existing music object.
noteworthy and note info strings. For as_music(), a
complete music string is assumed for notes when info = NULL.
optional lyrics object or NA, attached to output as an
attribute.
character, store the key signature as a music attribute. Defaults
to "c". See details.
character, store the time signature as a music attribute.
Defaults to "4/4". See details.
character or NA, defaults to "2 = 60". See details.
NULL or character, represent accidentals, "flat" or
"sharp".
NULL or character, the timestep delimiter format, "space"
or "vector".
character, text annotations to attach to timesteps using
notate.
integer, timesteps for labels, defaults to starting from
time one.
depends on the function
With note info strings, you are required to enter something at every timestep, even if it is only the duration. This makes sense because if you do not enter something, there is simply no indication of a timestep. A nice feature of music strings is that explicit timesteps are achieved just by having notes present, allowing you to leave out durations entirely when they repeat, inheriting them from the previous timestep where duration was given explicitly. There is no need to enter the same number across consecutive timesteps; the first will suffice and the rest are automatically filled in for you when the object is constructed.
musical() returns a scalar logical result indicating whether all timesteps
contain exclusively valid entries.
as_music() can be used to coerce to the music class. Coercion will fail
if the string is not musical. The music class has its own print() and
summary() methods. music objects are primarily intended to represent an
aggregation of a noteworthy object and a noteinfo. You can optionally
fold in a lyrics object as well. However, for music data analysis, any
operations will involve first splitting the object into its component parts.
The value of this class is for the more efficient data entry it provides.
When accidentals or format are NULL, these settings are inferred from
the musical string input. When mixed formats are present, flats are the
default for accidentals.
Other attributes are attached to a music object. key uses the tabr
syntax, e.g., "c", "b_", "f#m", etc. time and tempo use the
LilyPond string format. For music programming and analysis, key, time and
tempo can most likely be ignored. They are primarily relevant when
rendering a music snippet directly from a music object with LilyPond.
These additional attributes provide more complete context for the rendered
sheet music.
If you plan to render music snippets from a music object that you are
defining from a new character string, and the context you have in mind is a
stringed and fretted instrument like guitar, you can specify string numbers
at the end of each timestep with numbers following a semicolon delimiter.
This would still precede any * timestep multiplier number. See examples.
Note that if you convert a music object to a phrase object, you are changing
contexts. The phrase object is the simplest LilyPond-format music structure.
Coercion with phrase() strips all attributes of a music object and
retains only notes, note info and string numbers.
# note durations inherit from previous timestep if missing
x <- "a#4-+ b_[staccato] c,x d''t8( e)( g_')- a4 c,e_,g, ce_g4. a~8 a1"
is_music(x)
#> [1] FALSE
musical(x)
#> [1] TRUE
x <- as_music(x)
is_music(x)
#> [1] TRUE
x
#> <Music string>
#> Format: space-delimited time
#> Values: b_4-+ b_4[staccato] c,4x d''t8( et8)( g_'t8)- a4 <c,e_,g,>4 <ce_g>4. a~8 a1
y <- lyrics_template(x)
y[3:8] <- strsplit("These are some song ly- rics", " ")[[1]]
y
#> <Lyrics string>
#> Format: space-delimited time
#> Values: . . These are some song ly- rics . . .
x <- as_music(x, lyrics = y, accidentals = "sharp")
summary(x)
#> <Music string>
#> Timesteps: 11 (9 notes, 2 chords)
#> Octaves: tick
#> Accidentals: sharp
#> Key signature: c
#> Time signature: 4/4
#> Tempo: 2 = 60
#> Lyrics: . . These are some song ly- rics . ...
#> Format: space-delimited time
#> Values: a#4-+ a#4[staccato] c,4x d''t8( et8)( f#'t8)- a4 <c,d#,g,>4 <cd#g>4. a~8 a1
# Starting string = 5: use ';5'. Carries over until an explicit change.
x <- "a,4;5*5 b,4-+ c4[staccato] cgc'e'~4 cgc'e'1 e'4;2 c';3 g;4 c;5 ce'1;51"
x <- as_music_df(as_music(x))
x$string
#> [1] "5" "5" "5" "5" "5" "5" "5" "5432" "5432" "2"
#> [11] "3" "4" "5" "51"