use strict;
use warnings;
use Data::Dumper;


my %config;

foreach my $line (<DATA>) {
    if($line =~ m/^(\w+)\s*=\s*(.*?)\s*$/) {
        $config{$1} = [ split(/\s*;\s*/, $2) ];
    }
}

print Dumper(\%config);



__DATA__
inc_albums=a; list; of; albums; to; include
inc_genres=a; list; of; genres; to; include
inc_artists=a; list; of; artists; to; include
inc_songs=a; list; of; songs; to; include
inc_year=   a;  list;   of; years;  to; include
exc_albums= a;  list;   of; albums; to; exclude
exc_genres=a; list; of;genres;to;exclude
exc_artists=a; list; of; artists ;to; exclude
exc_songs=a; list; of; songs;to; exclude  
exc_year=a; list; of  ; years; to; exclude
[download]

Both of which produce a hash or lists like:

$VAR1 = {
          'inc_genres' => [
                            'a',
                            'list',
                            'of',
                            'genres',
                            'to',
                            'include'
                          ],
          'inc_year' => [
                          'a',
                          'list',
                          'of',
                          'years',
                          'to',
                          'include'
                        ],
          'exc_albums' => [
                            'a',
                            'list',
                            'of',
                            'albums',
                            'to',
                            'exclude'
                          ],
          'inc_albums' => [
                            'a',
                            'list',
                            'of',
                            'albums',
                            'to',
                            'include'
                          ],
          'exc_year' => [
                          'a',
                          'list',
                          'of',
                          'years',
                          'to',
                          'exclude'
                        ],
          'exc_songs' => [
                           'a',
                           'list',
                           'of',
                           'songs',
                           'to',
                           'exclude'
                         ],
          'inc_artists' => [
                             'a',
                             'list',
                             'of',
                             'artists',
                             'to',
                             'include'
                           ],
          'inc_songs' => [
                           'a',
                           'list',
                           'of',
                           'songs',
                           'to',
                           'include'
                         ],
          'exc_artists' => [
                             'a',
                             'list',
                             'of',
                             'artists',
                             'to',
                             'exclude'
                           ],
          'exc_genres' => [
                            'a',
                            'list',
                            'of',
                            'genres',
                            'to',
                            'exclude'
                          ]
        };
[download]

You might also consider using a module. There are many for reading and writing configuration files, supporting all sorts of formats. You may learn less about regular expressions, but you might also finish your project with less time and effort. Searching CPAN for config will find some of the available modules. You might have a look to see if there is something you like, or to get ideas how to do your own.