NAME

Music::ToRoman - Convert notes and chords to Roman numeral notation

VERSION

version 0.0701

SYNOPSIS

  use Music::ToRoman;

  my $mtr = Music::ToRoman->new(
    scale_note => 'A',
    scale_name => 'minor',
  );
  my $roman = $mtr->parse('Am'); # i (minor)
  $roman = $mtr->parse('Bo');    # iio (diminished)
  $roman = $mtr->parse('CM');    # III (major)
  $roman = $mtr->parse('C');     # III (major)
  $roman = $mtr->parse('Em7');   # v7 (minor seventh)
  $roman = $mtr->parse('A+');    # I+ (augmented)
  $roman = $mtr->parse('BbM');   # bII (flat-two major)
  $roman = $mtr->parse('Cm9/G'); # iii9/VII

  # Also:
  $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('E7'); # v7
  $roman = $mtr->parse('F#'); # vi
  $roman = $mtr->parse('G');  # VII

DESCRIPTION

Music::ToRoman converts chords to Roman numeral notation. Also individual "chordless" notes may be converted given a diatonic mode scale_name.

For example usage, check out the tests for this distribution and the files eg/roman and eg/basslines in Music::BachChoralHarmony.

ATTRIBUTES

scale_note

Note on which the scale is based. This can be one of C, Cb, C#, D, Db, D# ...

Default: C

scale_name

Name of the scale. The diatonic mode names supported are:

  ionian / major
  dorian
  phrygian
  lydian
  mixolydian
  aeolian / minor
  locrian

Default: major

chords

Are we given chords to parse with major ("M") and minor ("m") designations?

Default: 1

If this is set to 0, single notes may be used to return the major/minor Roman numeral for the given diatonic mode scale_name.

METHODS

new()

  $mtr = Music::ToRoman->new(%arguments);

Create a new Music::ToRoman object.

parse()

  $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.

This can be overridden by parsing say, BM7 (B major seven), thus producing II7 in the key of A minor.

As expected, if a major/minor chord designation is not provided, "M" major is assumed.

If the chords attribute is off and a single note is given, the diatonic mode of the scale_name is used to find the correct Roman numeral representation.

SEE ALSO

Moo

List::MoreUtils

Music::Scales

https://en.wikipedia.org/wiki/Roman_numeral_analysis

AUTHOR

Gene Boggs <gene@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2018 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.

cpanm Music::ToRoman

perl -MCPAN -e shell
install Music::ToRoman