case 'song_artist':
                foreach ($objects as $object_id) {
                    if ($include) {
                        $string .= "<artist id=\"" . $object_id . "\">\n";
                        $sql        = "SELECT DISTINCT `album_map`.`album_id` FROM `album_map` WHERE `album_map`.`object_id` = ? AND `album_map`.`object_type` = 'song';";