My genre dropdown is not showing .

<tr>
                <th>
                    <label for="genre">Genre</label>
                </th>
                <td>
                   <select name="genre" id="genre">
    <option value="">Select One</option>
        <?php
        $genre_arrayy = genre_array();
        foreach ($genre_arrayy as $category=>$options) {
          echo "<optgroup label=\"$category\">";
          foreach ($options as $option) {
            echo "<option value=\"$option\"";
            if (isset($genre) && $genre==$option) {
              echo " selected";
            }
            echo ">$option</option>";
          }
          echo "</optgroup>";
        }
        ?>
</select> 

                </td>
            </tr>
function genre_array($category = null) {
  $category = strtolower($category);
  include("connection.php");

  try {
    $sql = "SELECT genre, category"
      . " FROM Genres "
      . " JOIN Genre_Categories "
      . " ON Genres.genre_id = Genre_Categories.genre_id ";
    if (!empty($category)) {
      $results = $db->prepare($sql 
          . " WHERE LOWER(category) = ?"
          . " ORDER BY genre");
      $results->bindParam(1,$category,PDO::PARAM_STR);
    } else {
      $results = $db->prepare($sql . " ORDER BY genre");
    }
    $results->execute();
  } catch (Exception $e) {
    echo "bad query";
  }
  $genres = array();
  while ($row = $results->fetch(PDO::FETCH_ASSOC)) {
      $genres[$row["category"]][] = $row["genre"];
  }
  return $genres;
}