Text to Guidonian Melodies

I'm a programming musician. Maybe that's "musical programmer." But it's an exciting Saturday night in Geekville. What to do? Hmmm...

tl;dr: guidonian

While browsing through CPAN, I noticed JMATES' curious module Music::Guidonian and thought I'd puzzle it out.

Seems that "In Medieval music, the Guidonian hand was a mnemonic device used to assist singers in learning to sight-sing" (from wikipedia).

For the module, and the purposes of the this program, pitches are basically assigned to elements of text - for instance the vowels.

On with the show!

This program uses the venerable Getopt::Long module to allow your code to easily consume command-line arguments. For musical things, Music::Guidonian, Music::Scales, and MIDI::Util are used. If a text file is given, instead of a string of text, Mojo::File comes into action.

The program accepts a number of command-line arguments, all of which have a default set (except for the "--file", which is undef).

This is either the name of the scale to use, or a maximum number for random intervals of half-steps. So the next thing the program does is either get a list of seven random integer interval numbers OR compute the size of the intervals between scale degrees:

if ($opts{rand}) { 
    # Get random intervals
    @intervals = map { int(rand $opts{rand}) + 1 } 1 .. 7;
}
else { 
    # Get the named scale intervals
    my @scale  = (get_scale_nums($opts{scale}), 12);
    @intervals = map { $scale[$_ + 1] - $scale[$_]} 0 .. $#scale - 1;
}

This is then used in the next step, which is to instantiate a new Music::Guidonian object:

my $mg = Music::Guidonian->new(
  key_set => {
    intervals => \@intervals,
    keys      => [ split //, $opts{regex} ],
    min       => $opts{min},
    max       => $opts{max},
  }
);

If we are given a file, reassign the text to its contents:

if ($opts{file}) {
    my $file = Mojo::File->new($opts{file});
    $opts{text} = $file->slurp;
}

Extract the vowels:

$opts{text} =~ s/([$opts{regex}])[$opts{regex}]/$1/g;                                                                                                                        
my @vowels = lc($opts{text}) =~ m/([$opts{regex}])/g;

Create and call a Music::Guidonian iterator:

my $iter = $mg->iterator(\@vowels);
my $phrase = $iter->();

Create a MIDI score, add the notes of the phrase to it, and play each as a quarter-note:

my $score = setup_score(bpm => $opts{bpm}, patch => $opts{patch}, volume => $opts{vol});

for (1 .. $opts{num}) {
    $score->n('qn', $_) for @$phrase;
}

$score->write_score("$0.mid");

So what does this sound like?

perl guidonian -s minor -t 'Lorem ipsum dolor sit amet consectetur adipiscing elit sed do eiusmod tempor incididunt ut labore et dolore magna aliqua'

And here are what the lyrics of The Beatles, Penny Lane sounds like:

perl guidonian -f ~/Documents/lit/Beatles/Penny_Lane.txt