tax_before_title.php

<?php //do not include this php tag

add_filter( 'genesis_post_title_output', 'modified_classi_p_title');
function modified_classi_p_title($title) {
  global $post;
  
  $customcat = '<span id="cat_classi">' . get_the_term_list($post->ID, 'classi_cat') . '</span>';
  $title = $customcat . $title;
  
  return $title;
}