my %hash = (
    genre => 'Rap',
    artist => 'Mozart',
);

sub genre  () { $hash {'genre'} }
sub artist () { $hash {'artist'} }
sub album  () { $hash {'album'} }

my $file = 'some_file.mp3';

$_ = "RULE = (genre eq Rap or genre eq HipHop) and artist ne RunDMC to /music/Other";

if(s/^RULE\s*=\s*//) {
    my ($cond, $target) = split /\s+to\s+/, $_;
    eval $cond and print "rename $file, $target/$file\n";
}