Helper functions for key signature information.
keys(type = c("all", "sharp", "flat"))
key_is_natural(key)
key_is_sharp(key)
key_is_flat(key)
key_n_sharps(key)
key_n_flats(key)
key_is_major(key)
key_is_minor(key)character vector.
The keys() function returns a vector of valid key signature IDs. These IDs
are how key signatures are specified throughout tabr, including in the
other helper functions here via key. Like the other functions here,
key_is_sharp() and key_is_flat() are for key signatures, not single
pitches whose sharp or flat status is always self-evident from their notation.
Major and minor keys are also self-evident from their notation, but
key_is_major() and key_is_minor() can still be useful when programming.
keys()
#> [1] "c" "g" "d" "a" "e" "b" "f#" "c#" "f" "b_" "e_" "a_"
#> [13] "d_" "g_" "c_" "am" "em" "bm" "f#m" "c#m" "g#m" "d#m" "a#m" "dm"
#> [25] "gm" "cm" "fm" "b_m" "e_m" "a_m"
key_is_natural(c("c", "am", "c#"))
#> [1] TRUE TRUE FALSE
x <- c("a", "e_")
key_is_sharp(x)
#> [1] TRUE FALSE
key_is_flat(x)
#> [1] FALSE TRUE
key_n_sharps(x)
#> [1] 3 0
key_n_flats(x)
#> [1] 0 3