#!/usr/bin/perl

$key = uc(shift || "C");
$mode = lc(shift || "major");

@notes = qw(A A# B C C# D D# E F F# G G# A A# B C C# D D# E F F# G G#);
%modes = ("major", -1, "ionian", -1, "dorian", 0, "phrygian", 1, "lydian", 2, 
          "mixolydian", 3, "aeolian", 4, "locrian", 5);
@steps = qw(2 2 1 2 2 2 1);

$notematch = join "|", @notes;
if (($key !~ /($notematch)/) || !(exists $modes{$mode})) {die "Invalid key or mode!\n"}


while ($notes[0] ne $key) {
       push(@notes, shift(@notes));
}

for (0 .. $modes{"$mode"}) {
       push(@steps, shift(@steps));
}

unshift(@steps, 0);

foreach $i (@steps) {
       $index += $i;
       print $notes[$index] . " ";
}