NAME

Music::Intervals - Mathematical breakdown of musical intervals

VERSION

version 0.0507

SYNOPSIS

  use Music::Intervals;

  my $m = Music::Intervals->new(
    notes    => [qw/C E G B/], # Default: C major scale
    size     => 3,             # Must be <= the notes
    chords   => 1,             # Required for chord names
    justin   => 1,             # Required for natural_*
    equalt   => 1,             # Required for eq_tempered_*
    freqs    => 1,             # Required for *_frequencies
    interval => 1,             # Required for *_intervals
    cents    => 1,             # Required for *_cents
    prime    => 1,             # Required for prime factors
    integer  => 1,             # Required for integer notation
  );

  $m->process;

  # Then
  print Dumper # any of:
    $m->chord_names,
    $m->natural_frequencies,
    $m->natural_intervals,
    $m->natural_cents,
    $m->natural_prime_factors,
    $m->eq_tempered_frequencies,
    $m->eq_tempered_intervals,
    $m->eq_tempered_cents,
    $m->integer_notation,
  ;

  # Find known intervals
  $name  = $m->by_ratio($ratio);
  $ratio = $m->by_name($interval_name);

  # Show all the known intervals:
  perl -MData::Dumper -MMusic::Intervals::Ratios -e'print Dumper $Music::Intervals::Ratios::ratio'

DESCRIPTION

A Music::Intervals object shows the mathematical break-down of musical notes, intervals and chords.

This module reveals the "guts" within a given tonality. And by guts I mean, the measurements of the notes and the intervals between them.

ATTRIBUTES

chords

Show chord names.

Default: 0

rootless

Show chord names with no root.

Default: 0

equalt

Show equal temperament.

Default: 0

justin

Show just intonation.

Default: 0

integer

Show integer notation.

Default: 0

cents

Show the logarithmic units of measure.

Default: 0

freqs

Show frequencies.

Default: 0

interval

Show note intervals.

Default: 0

prime

Show prime factorization.

Default: 0

octave

The octave to use.

Default: 4

concert

Concert pitch.

Default: 440

size

Chord size

Default: 3

tonic

The root of the computations.

Default: C

* Currently (and for the foreseeable future) this will remain the only value that produces sane results.

semitones

Number of notes in the scale.

Default: 12

temper

Physical distance between notes.

Default: semitones * 100 / log(2)

notes

The actual notes to use in the computation.

Default: [ C D E F G A B ]

The list of notes may be any of the keys in the Music::Intervals::Ratios ratio hashref. This is very very long and contains useful intervals such as those of the common scale and even the Pythagorean intervals, too.

A few examples:

 * [qw( C E G )]
 * [qw( C D D# )]
 * [qw( C D Eb )]
 * [qw( C D D# Eb E E# Fb F )]
 * [qw( C 11h 7h )]
 * [qw( C pM3 pM7 )]

For natural_intervals this last example produces the following:

 'C pM3 pM7' => {
   'C pM3' => { '81/64' => 'Pythagorean major third' },
   'C pM7' => { '243/128' => 'Pythagorean major seventh' },
   'pM3 pM7' => { '3/2' => 'perfect fifth' }
 }

Note that case matters for interval names. For example, "M" means major and "m" means minor.

midikey

Default: 69

chord_names

Computed hashref

eq_tempered_cents

Computed hashref

eq_tempered_frequencies

Computed hashref

eq_tempered_intervals

Computed hashref

integer_notation

Computed hashref

natural_cents

Computed hashref

natural_frequencies

Computed hashref

natural_intervals

Computed hashref

natural_prime_factors

Computed hashref

METHODS

new()

  $x = Music::Intervals->new(%arguments);

Create a new Music::Intervals object.

process()

Do the actual computations!

dyads()

Return pairs of the given combinations with fractional and pitch ratio parts.

ratio_factorize()

Return the dyadic fraction as a prime factored expression.

by_name()

 $ratio = $m->by_name('C');
 # { ratio => '1/1', name => 'unison, perfect prime, tonic' }

Return a known ratio or undef.

by_ratio()

 $name = $m->by_ratio('1/1');
 # { 'symbol' => 'C', 'name' => 'unison, perfect prime, tonic' }

Return a known ratio name or undef.

SEE ALSO

The t/ tests and eg/ example in this distribution

For the time being, you will need to look at the source of Music::Intervals::Ratios for the note and interval names.

Music::Intervals::Numeric for numeric-only note-intervals

https://github.com/ology/Music/blob/master/intervals - The predecessor to this module

http://en.wikipedia.org/wiki/List_of_musical_intervals

http://en.wikipedia.org/wiki/Equal_temperament

http://en.wikipedia.org/wiki/Just_intonation

AUTHOR

Gene Boggs <gene@cpan.org>

COPYRIGHT AND LICENSE

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.