Music::ToRoman - Convert notes and chords to Roman numeral notation
version 0.1701
use Music::ToRoman; my $mtr = Music::ToRoman->new( scale_note => 'A', scale_name => 'minor', ); my $roman = $mtr->parse('Am'); # i (minor) $roman = $mtr->parse('Bdim'); # iio (diminished) $roman = $mtr->parse('B dim'); # ii o $roman = $mtr->parse('Bo'); # iio $roman = $mtr->parse('Bø'); # ii7b5 (half-diminished) $roman = $mtr->parse('Bb'); # bII (flat-two major) $roman = $mtr->parse('CM'); # III (major) $roman = $mtr->parse('C'); # III $roman = $mtr->parse('Cm9/G'); # iii9/VII (minor-nine with seven bass) $roman = $mtr->parse('Cm9/Bb'); # iii9/bii (minor-nine with flat-two bass) $roman = $mtr->parse('Dsus4'); # IVsus4 (suspended) $roman = $mtr->parse('D sus4'); # IV sus4 $roman = $mtr->parse('D maj7'); # IV maj7 (major seventh) $roman = $mtr->parse('DMaj7'); # IVmaj7 $roman = $mtr->parse('D△7'); # IVmaj7 $roman = $mtr->parse('E7'); # V7 (dominant seventh) $roman = $mtr->parse('Fmin7'); # vimin7 (minor seventh) $roman = $mtr->parse('G+'); # VII+ (augmented) $mtr = Music::ToRoman->new( scale_note => 'A', scale_name => 'dorian', chords => 0, ); $roman = $mtr->parse('A'); # i $roman = $mtr->parse('B'); # ii $roman = $mtr->parse('C'); # III $roman = $mtr->parse('D'); # IV $roman = $mtr->parse('E'); # v $roman = $mtr->parse('F#'); # vi $roman = $mtr->parse('G'); # VII $roman = $mtr->parse('Amin7'); # imin7 $roman = $mtr->parse('Bo'); # iio $roman = $mtr->parse('CMaj7'); # IIImaj7 $roman = $mtr->parse('D7'); # IV7 $roman = $mtr->parse('Em'); # v
Music::ToRoman converts named chords to Roman numeral notation. Also individual "chordless" notes may be converted given a diatonic mode scale_name.
Music::ToRoman
Note on which the scale is based. Default: C
C
This must be an uppercase letter from A-G either alone or followed by # or b.
A-G
#
b
Note that the keys of A# and D# are better represented by Gb and Eb respectively, because the scales contain notes with double sharps. Double flat scales are not supported.
A#
D#
Gb
Eb
Name of the scale. Default: major
major
The diatonic mode names supported are:
ionian / major dorian phrygian lydian mixolydian aeolian / minor locrian
Note on which the major scale is based. Default: 'C'
'C'
This must be an uppercase letter from A-G and followed by a # or b.
This attribute is required when the scale_note is set to a double-sharp, and the scale_name is not major (or ionian).
ionian
Again, double flat scales are not supported.
Are we given chords to parse with major (M) or minor (m/o/dim/ø) designations?
M
m
o
dim
ø
Default: 1
1
If this is set to 0, single notes can be used to return the major/minor Roman numeral for the given diatonic mode scale_name.
0
Show the progress of the parse method. Default 0
$mtr = Music::ToRoman->new( scale_note => $note, scale_name => $name, major_tonic => $tonic, chords => $chords, verbose => $verbose, );
Create a new Music::ToRoman object.
$roman = $mtr->parse($chord);
Parse a note or chord name into a Roman numeral representation.
For instance, the Roman numeral representation for the aeolian (or minor) mode is: i ii III iv v VI VII - where the case indicates the major/minor status of the given chord.
aeolian
i ii III iv v VI VII
This can be overridden by parsing say, B7 (B dominant seventh), thus producing II7.
B7
II7
If a major/minor chord designation is not provided, M major is assumed.
If the chords attribute is set to 0, the scale_name is used to figure out the correct Roman numeral representation.
A diminished chord may be given as either o or dim. Half-diminished (m7b5) chords can be given as ø. A decoration of △ may be given for say the △7 major seventh chord.
m7b5
△
△7
Parsing a double flatted chord will only work in select cases.
List::MoreUtils
Moo
Music::Note
Music::Scales
https://en.wikipedia.org/wiki/Roman_numeral_analysis
For example usage, check out the test files t/*-methods.t in this distribution. Also see eg/roman and eg/basslines in Music::BachChoralHarmony.
App::MusicTools vov is the reverse of this module, and is significantly powerful.
vov
Dan Book (DBOOK) for the list rotation logic
Gene Boggs <gene@cpan.org>
This software is copyright (c) 2019 by Gene Boggs.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
To install Music::ToRoman, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Music::ToRoman
CPAN shell
perl -MCPAN -e shell install Music::ToRoman
For more information on module installation, please visit the detailed CPAN module installation guide.