Primus got me interested in creating MIDI chords in Perl. So I started researching and this is what I came up with. The BASE_NOTE can be attained in different ways depending on which module you are using. See the example.

Update: NOTE: This only creates the note values. It does not play them.

use MIDI; # for example usage
my %chords = (
    major   => [0, 4, 7, 12],
    minor   => [0, 3, 7, 12],
    major7  => [0, 4, 7, 11],
    minor7  => [0, 3, 7, 10],
    minor75 => [0, 3, 6, 10],
    dim     => [0, 3, 6, 9],
    dom7    => [0, 4, 7, 10],
    major9  => [0, 4, 7, 11, 14],
    minor9  => [0, 3, 7, 10, 14],
);

my $note = 'Cs5'; # C sharp, 5th octave
my $base = $MIDI::note2number{$note}; # 61
my @CsMajor5 = chord($base, @{$chords{major}});
print "C sharp major chord, 5th octave: @CsMajor5\n";
# output: C sharp major chord, 5th octave: 61 65 68 73

sub chord {
# BASE_NOTE is the numeric value of the first note
# CHORD is a chord array
  my ($base, @chord) = @_;
  return map { $_ += $base; } @chord;
}

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Chord Values for MIDI::Simple
by Mr. Muskrat (Canon) on Feb 13, 2003 at 17:25 UTC
    Here is a MIDI::Simple version:
    use MIDI::Simple;
my %chords = (
    major   => [0, 4, 7, 12],
    minor   => [0, 3, 7, 12],
    major7  => [0, 4, 7, 11],
    minor7  => [0, 3, 7, 10],
    minor75 => [0, 3, 6, 10],
    dim     => [0, 3, 6, 9],
    dom7    => [0, 4, 7, 10],
    major9  => [0, 4, 7, 11, 14],
    minor9  => [0, 3, 7, 10, 14],
);

sub chord {
# chord(NOTE, CHORD);
# NOTE is the base note of the chord (numeric or name)
# CHORD is a reference to the chord array
# uses MIDI::Simple's interval procedure
# returns a list of notes (numeric or name) based on the format of NOT
+E
  my ($note, $chord) = @_;
  return interval $chord, $note;
}

my $note = 'Cs5'; # C sharp, 5th octave (D flat)
my @CsMajor5 = chord2($note, $chords{major});
print "C sharp major chord, 5th octave: @CsMajor5\n";
# displays: C sharp major chord, 5th octave: Df5 F5 Af5 Df6

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[d/l]
Re: Chord Values for MIDI
by Anonymous Monk on Feb 12, 2003 at 22:07 UTC
    Cool but where can i get MIDI.pm? I tried doing this: 
    C:\>ppm
PPM interactive shell (2.1.5) - type 'help' for available commands.
PPM> install MIDI
Install package 'MIDI?' (y/N): y
Installing package 'MIDI'...
Error installing package 'MIDI': Could not locate a PPD file for packa
+ge MIDI
PPM> quit
Quit!

    [download]
    Can you help?
[reply]
[d/l]

      ActiveState has it listed as MIDI-Perl.

      So just do ppm install MIDI-Perl and it should install for you.

[reply]
[d/l]
        That worked thanks. But I don't hear any sound? I have speakers and can hear most stuff (i.e. Realplayer and stuff off the net) Do I need special hardware too?
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